https://www.openstreetmap.org/images/osm_logo.png" alt="" /> OpenStreetMap (openstreetmap.org) is a global collaborative mapping project, which offers maps and map data released with an open license, encouraging free re-use and re-distribution. The data is created by a large community of volunteers who use a variety of simple on-the-ground surveying techniques, and wiki-syle editing tools to collaborate as they create the maps, in a process which is open to everyone. The project originated in London, and an active community of mappers and developers are based here. Mapping work in London is ongoing (and you can help!) but the coverage is already good enough for many uses.
Browse the map of London on OpenStreetMap.org
The whole of England updated daily:
For more details of downloads available from OpenStreetMap, including downloading the whole planet, see 'planet.osm' on the wiki.
Download small areas of the map by bounding-box. For example this URL requests the data around Trafalgar Square:
http://api.openstreetmap.org/api/0.6/map?bbox=-0.13062,51.5065,-0.12557,51.50969
Data filtered by "tag". For example this URL returns all elements in London tagged shop=supermarket:
http://www.informationfreeway.org/api/0.6/*[shop=supermarket][bbox=-0.48,51.30,0.21,51.70]
The format of the data is a raw XML represention of all the elements making up the map. OpenStreetMap is composed of interconnected "nodes" and "ways" (and sometimes "relations") each with a set of name=value pairs called "tags". These classify and describe properties of the elements, and ultimately influence how they get drawn on the map. To understand more about tags, and different ways of working with this data format refer to the following pages on the OpenStreetMap wiki.
Rather than working with raw map data, you may prefer to embed maps from OpenStreetMap on your website with a simple bit of javascript. You can also present overlays of other data, in a manner very similar to working with google maps. In fact you can even use the google maps API to do this. See OSM on your own website for details and links to various javascript map libraries.
The OpenStreetMap project aims to attract large numbers of contributors who all chip in a little bit to help build the map. Although the map editing tools take a little while to learn, they are designed to be as simple as possible, so that everyone can get involved. This project offers an exciting means of allowing local London communities to take ownership of their part of the map.
Read about how to Get Involved and see the London page for details of OpenStreetMap community events.
Important Note: This item is in mature support as of July 2021. A new version of this item is available for your use. Esri recommends updating your maps and apps to use the new version.This map is designed to be used as a general reference map for informational and educational purposes as well as a basemap by GIS professionals and other users for creating web maps and web mapping applications.The map was developed by National Geographic and Esri and reflects the distinctive National Geographic cartographic style in a multi-scale reference map of the world. The map was authored using data from a variety of leading data providers, including Garmin, HERE, UNEP-WCMC, NASA, ESA, USGS, and others.This reference map includes administrative boundaries, cities, protected areas, highways, roads, railways, water features, buildings and landmarks, overlaid on shaded relief and land cover imagery for added context. The map includes global coverage down to ~1:144k scale and more detailed coverage for North America down to ~1:9k scale.Map Note: Although small-scale boundaries, place names and map notes were provided and edited by National Geographic, boundaries and names shown do not necessarily reflect the map policy of the National Geographic Society, particularly at larger scales where content has not been thoroughly reviewed or edited by National Geographic.Data Notes: The credits below include a list of data providers used to develop the map. Below are a few additional notes:Reference Data: National Geographic, Esri, Garmin, HERE, iPC, NRCAN, METILand Cover Imagery: NASA Blue Marble, ESA GlobCover 2009 (Copyright notice: © ESA 2010 and UCLouvain)Protected Areas: IUCN and UNEP-WCMC (2011), The World Database on Protected Areas (WDPA) Annual Release. Cambridge, UK: UNEP-WCMC. Available at:www.protectedplanet.net.Ocean Data: GEBCO, NOAA
http://inspire.ec.europa.eu/metadata-codelist/LimitationsOnPublicAccess/INSPIRE_Directive_Article13_1dhttp://inspire.ec.europa.eu/metadata-codelist/LimitationsOnPublicAccess/INSPIRE_Directive_Article13_1d
Coal resource maps for the whole of the UK have been produced by the British Geological Survey as a result of joint work with Department of Trade and Industry and the Coal Authority. The Coal Resources Map is a Map of Britain depicting the spatial extent of the principal coal resources. The map shows the areas where coal and lignite are present at the surface and also where coal is buried at depth beneath younger rocks. The maps are intended to be used for resource development, energy policy, strategic planning, land-use planning, the indication of hazard in mined areas, environment assessment and as a teaching aid. In addition to a general map of coal resources for Britain data also exists for the six inset maps: Scotland; North-East; North-West; East Pennines; Lancashire, North Wales and the West Midlands; South Wales, Forest of Dean and Bristol. Available as a paper map, flat or folded, from BGS Sales or as a pdf on a CD if requested.
Open Government Licence 3.0http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
License information was derived automatically
The Moorland Change Map (MCM) is a vector dataset which shows whether the uplands monitored contain change during the period of monitoring (Approximately the moorland burning season of Oct to Apr. The MCM is an earth observation derived product, using the Sentinel-2 satellites Validation of the the results happens for each year per upland and Nationally. The validation shows the accuracy of the MCM results and are available in the associated Excel spreadsheet.
PLEASE NOTE: This data product is not available in Shapefile format or KML at https://naturalengland-defra.opendata.arcgis.com/datasets/Defra::living-england-habitat-map-phase-4/about, as the data exceeds the limits of these formats. Please select an alternative download format.This data product is also available for download in multiple formats via the Defra Data Services Platform at https://environment.data.gov.uk/explore/4aa716ce-f6af-454c-8ba2-833ebc1bde96?download=true.The Living England project, led by Natural England, is a multi-year programme delivering a satellite-derived national habitat layer in support of the Environmental Land Management (ELM) System and the Natural Capital and Ecosystem Assessment (NCEA) Pilot. The project uses a machine learning approach to image classification, developed under the Defra Living Maps project (SD1705 – Kilcoyne et al., 2017). The method first clusters homogeneous areas of habitat into segments, then assigns each segment to a defined list of habitat classes using Random Forest (a machine learning algorithm). The habitat probability map displays modelled likely broad habitat classifications, trained on field surveys and earth observation data from 2021 as well as historic data layers. This map is an output from Phase IV of the Living England project, with future work in Phase V (2022-23) intending to standardise the methodology and Phase VI (2023-24) to implement the agreed standardised methods.The Living England habitat probability map will provide high-accuracy, spatially consistent data for a range of Defra policy delivery needs (e.g. 25YEP indicators and Environment Bill target reporting Natural capital accounting, Nature Strategy, ELM) as well as external users. As a probability map, it allows the extrapolation of data to areas that we do not have data. These data will also support better local and national decision making, policy development and evaluation, especially in areas where other forms of evidence are unavailable. Process Description: A number of data layers are used to inform the model to provide a habitat probability map of England. The main sources layers are Sentinel-2 and Sentinel-1 satellite data from the ESA Copericus programme. Additional datasets were incorporated into the model (as detailed below) to aid the segmentation and classification of specific habitat classes. Datasets used:Agri-Environment Higher Level Stewardship (HLS) Monitoring, British Geological Survey Bedrock Mapping 1:50k, Coastal Dune Geomatics Mapping Ground Truthing, Crop Map of England (RPA), Dark Peak Bog State Survey, Desktop Validation and Manual Points, EA Integrated Height Model 10m, EA Saltmarsh Zonation and Extent, Field Unit NEFU, Living England Collector App NEFU/EES, Long Term Monitoring Network (LTMN), Lowland Heathland Survey, National Forest Inventory (NFI), National Grassland Survey, National Plant Monitoring Scheme, NEFU Surveys, Northumberland Border Mires, OS Vector Map District , Priority Habitats Inventory (PHI) B Button, European Space Agency (ESA) Sentinel-1 and Sentinel-2 , Space2 Eye Lens: Ainsdale NNR, Space2 Eye Lens: State of the Bog Bowland Survey, Space2 Eye Lens: State of the Bog Dark Peak Condition Survey, Space2 Eye Lens: State of the Bog (MMU) Mountain Hare Habitat Survey Dark Peak, Uplands Inventory, West Pennines Designation NVC Survey, Wetland Inventories, WorldClim - Global Climate DataFull metadata can be viewed on data.gov.uk.
Colourful and easy to use, Bartholomew’s maps became a trademark series. The maps were popular and influential, especially for recreation, and the series sold well, particularly with cyclists and tourists. To begin with, Bartholomew printed their half-inch maps in Scotland as stand-alone sheets known as 'District Sheets' and by 1886 the whole of Scotland was covered. They then revised the maps into an ordered set of 29 sheets covering Scotland in a regular format. This was first published under the title Bartholomew’s Reduced Ordnance Survey of Scotland. The half-inch maps of Scotland formed the principal content for Bartholomew's Survey Atlas of Scotland published in 1895. Bartholomew then moved south of the Border to the more lucrative but competitive market in England and Wales, whilst continuing to revise the Scottish sheets. The first complete coverage of Great Britain at the half-inch scale was achieved by 1903, and this is the layer shown here.The half-inch maps were distinctive for using different layers of colour to represent landscape relief. A subtle and innovative gradation of colour bands were employed for land at different heights. Lighter greens were used for low ground closest to sea-level, darker greens and browns for higher ground, with white used for mountain tops. Whilst layer colouring had been developed in Germany from the 1860s, Bartholomew's development of it was both innovative and influential. John Bartholomew junior (1831-1893) first used the firm's trademark layer colouring in Baddeley’s Thorough Guide to the English Lake District (1880). His son, John George Bartholomew (1860-1920), later went on to refine the style. You can see Bartholomew’s continued experimentation with layer colour palettes in the Cairngorms layer colour explorer ( http://geo.nls.uk/maps/bartholomew/layers/ )
Bartholomew based their half-inch maps on more detailed Ordnance Survey mapping at one-inch to the mile (1:63,360). The firm had published 'Reduced Ordnance Maps' of Scotland, England and Wales at this scale from the 1890s. These maps were progressively revised and updated with new information. Usually Bartholomew made revisions the sheets right up to the time of publication, so the date of publication is the best guide to the approximate date of the features shown on the map. You can view the dates of publication for the series at:
● Scotland: https://maps.nls.uk/series/bart_half_scotland.html
● England and Wales: https://maps.nls.uk/series/bart_half_england.html
http://inspire.ec.europa.eu/metadata-codelist/LimitationsOnPublicAccess/INSPIRE_Directive_Article13_1dhttp://inspire.ec.europa.eu/metadata-codelist/LimitationsOnPublicAccess/INSPIRE_Directive_Article13_1d
This layer of the GeoIndex shows the location of available 1:10000 scale digital geological maps within Great Britain. The Digital Geological Map of Great Britain project (DiGMapGB) has prepared 1:625 000, 1:250 000 and 1:50 000 scale datasets for England, Wales and Scotland. The datasets themselves are available as vector data in a variety of formats in which they are structured into themes primarily for use in geographical information systems (GIS) where they can be integrated with other types of spatial data for analysis and problem solving in many earth-science-related issues. The DiGMapGB-10 dataset is as yet incomplete, current work is concentrated on extending the geographical cover, especially to cover high priority urban areas.
Abstract copyright UK Data Service and data collection copyright owner.
The Access Network Map of England
is a national composite dataset of Access layers, showing analysis of extent of
Access provision for each Lower Super Output Area (LSOA), as a percentage or
area coverage of access in England. The ‘Access Network Map’ was developed by
Natural England to inform its work to improve opportunities for people to enjoy
the natural environment. This map shows, across England, the
relative abundance of accessible land in relation to where people
live. Due to issues explained below, the map does not, and cannot, provide
a definitive statement of where intervention is necessary. Rather,
it should be used to identify areas of interest which require further
exploration. Natural England believes that places where
people can enjoy the natural environment should be improved and created where
they are most wanted. Access Network Maps help support this work by
providing means to assess the amount of accessible land available in relation
to where people live. They combine all the available good quality data on
access provision into a single dataset and relate this to population.
This provides a common foundation for regional and national teams to use when
targeting resources to improve public access to greenspace, or projects that
rely on this resource. The Access Network Maps are compiled from the
datasets available to Natural England which contain robust, nationally
consistent data on land and routes that are normally available to the public
and are free of charge. Datasets contained in the aggregated
data:•
Agri-environment
scheme permissive access (routes and open access)•
CROW access land
(including registered common land and Section 16)•
Country Parks•
Cycleways (Sustrans
Routes) including Local/Regional/National and Link Routes•
Doorstep Greens•
Local Nature
Reserves•
Millennium Greens•
National Nature
Reserves (accessible sites only)•
National Trails•
Public Rights of
Way•
Forestry Commission
‘Woods for People’ data•
Village Greens –
point data only Due to the quantity and complexity of data
used, it is not possible to display clearly on a single map the precise
boundary of accessible land for all areas. We therefore selected a
unit which would be clearly visible at a variety of scales and calculated the
total area (in hectares) of accessible land in each. The units we
selected are ‘Lower Super Output Areas’ (LSOAs), which represent where
approximately 1,500 people live based on postcode. To calculate the
total area of accessible land for each we gave the linear routes a notional
width of 3 metres so they could be measured in hectares. We then
combined together all the datasets and calculated the total hectares of
accessible land in each LSOA. For further information about this data see the following links:Access Network Mapping GuidanceAccess Network Mapping Metadata Full metadata can be viewed on data.gov.uk.
Open Government Licence 3.0http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
License information was derived automatically
The Living England project, led by Natural England, is a multi-year programme delivering a satellite-derived national habitat layer in support of the Environmental Land Management (ELM) System and the Natural Capital and Ecosystem Assessment (NCEA) Pilot. The project uses a machine learning approach to image classification, developed under the Defra Living Maps project (SD1705 – Kilcoyne et al., 2017). The method first clusters homogeneous areas of habitat into segments, then assigns each segment to a defined list of habitat classes using Random Forest (a machine learning algorithm). The habitat probability map displays modelled likely broad habitat classifications, trained on field surveys and earth observation data from 2021 as well as historic data layers. This map is an output from Phase IV of the Living England project, with future work in Phase V (2022-23) intending to standardise the methodology and Phase VI (2023-24) to implement the agreed standardised methods.
The Living England habitat probability map will provide high-accuracy, spatially consistent data for a range of Defra policy delivery needs (e.g. 25YEP indicators and Environment Bill target reporting Natural capital accounting, Nature Strategy, ELM) as well as external users. As a probability map, it allows the extrapolation of data to areas that we do not have data. These data will also support better local and national decision making, policy development and evaluation, especially in areas where other forms of evidence are unavailable.
Process Description: A number of data layers are used to inform the model to provide a habitat probability map of England. The main sources layers are Sentinel-2 and Sentinel-1 satellite data from the ESA Copericus programme. Additional datasets were incorporated into the model (as detailed below) to aid the segmentation and classification of specific habitat classes.
Datasets used: Agri-Environment Higher Level Stewardship (HLS) Monitoring, British Geological Survey Bedrock Mapping 1:50k, Coastal Dune Geomatics Mapping Ground Truthing, Crop Map of England (RPA), Dark Peak Bog State Survey, Desktop Validation and Manual Points, EA Integrated Height Model 10m, EA Saltmarsh Zonation and Extent, Field Unit NEFU, Living England Collector App NEFU/EES, Long Term Monitoring Network (LTMN), Lowland Heathland Survey, National Forest Inventory (NFI), National Grassland Survey, National Plant Monitoring Scheme, NEFU Surveys, Northumberland Border Mires, OS Vector Map District , Priority Habitats Inventory (PHI) B Button, European Space Agency (ESA) Sentinel-1 and Sentinel-2 , Space2 Eye Lens: Ainsdale NNR, Space2 Eye Lens: State of the Bog Bowland Survey, Space2 Eye Lens: State of the Bog Dark Peak Condition Survey, Space2 Eye Lens: State of the Bog (MMU) Mountain Hare Habitat Survey Dark Peak, Uplands Inventory, West Pennines Designation NVC Survey, Wetland Inventories, WorldClim - Global Climate Data
A spatial indicator of ecological status for valuation of biodiversity across the UK, based on species occurrence records for eleven taxonomic groups (Bees, Birds, Bryophytes, Butterflies, Carabidae, Hoverflies, Isopoda, Ladybirds, Moths, Orthoptera and Vascular plants) was developed. UK species occurrence data were collated from the Biological Records Centre (BRC). The mean ecological status was calculated across all taxonomic groups for the 2000 to 2013 time period, relative to the species richness maximums from the 1970-1990 time period. This version supersedes the dataset 'UK ecological status map'.
This dataset provides information on 115 in United Kingdom as of March, 2025. It includes details such as email addresses (where publicly available), phone numbers (where publicly available), and geocoded addresses. Explore market trends, identify potential business partners, and gain valuable insights into the industry. Download a complimentary sample of 10 records to see what's included.
This is the land parcels (polygon) dataset for the UKCEH Land Cover Map of 2019 (LCM2019) representing Northern Ireland. It describes Northern Ireland's land cover in 2019 using UKCEH Land Cover Classes, which are based on UK Biodiversity Action Plan broad habitats. This dataset was derived from the corresponding LCM2019 20m classified pixels dataset. All further LCM2019 datasets for Northern Ireland are derived from this land parcel product. A range of land parcel attributes are provided. These include the dominant UKCEH Land Cover Class given as an integer value and a range of per-parcel pixel statistics to help assess classification confidence and accuracy; for a full explanation please refer to the dataset documentation. LCM2019 represents a suite of geospatial land cover datasets (raster and polygon) describing the UK land surface in 2019. These were produced at the UK Centre for Ecology & Hydrology by classifying satellite images from 2019. LCM2019 was simultaneously released with LCM2017 and LCM2018. These are the latest in a series of UKCEH land cover maps, which began with the 1990 Land Cover Map of Great Britain (now usually referred to as LCM1990) followed by UK-wide land cover maps LCM2000, LCM2007 and LCM2015. This work was supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability.
The Department for Business, Energy and Industrial Strategy have published a series of interactive maps. The maps bring together BEIS's Local Authority datasets into one place allowing users to view trends in fuel poverty, energy use and energy efficiency measures.
The themes of the map are: * Cavity wall and loft insulation * Fuel poverty * Domestic solar photovoltaic installations * Gas and electricity consumption
https://www.nationalarchives.gov.uk/doc/non-commercial-government-licence/version/2/https://www.nationalarchives.gov.uk/doc/non-commercial-government-licence/version/2/
The Peat Layer was produced by Natural England (ARM team) during June-October 2008, with the aim of identifying the extent of three classes of peaty soils for the purposes of the Partnership Project to Protect and Enhance Peat Soils (aka. The Peat Project). The Peat Project is a joint initiative of Defra, Natural England, the Environment Agency, Forestry Commission, Welsh Assembly Government, Countryside Council for Wales, Northern Ireland Environment Agency, Cadw and the Department for Energy and Climate Change, and aims to improve coordination between these partners in our efforts to understand, manage and restore peaty soils.BGS, Cranfield University (NSRI) and OS must be acknowledged in any reports or documents produced as a result of using the Peat layer.
https://eidc.ceh.ac.uk/licences/lcm-raster/plainhttps://eidc.ceh.ac.uk/licences/lcm-raster/plain
This dataset consists of the 25m raster version of the Land Cover Map 2015 (LCM2015) for Great Britain. The 25m raster product consists of two bands: Band 1 - raster representation of the majority (dominant) class per polygon for 21 target habitat classes; Band 2 - mean per polygon probability as reported by the Random Forest classifier (see supporting information). The 21 target classes are based on the Joint Nature Conservation Committee (JNCC) Broad Habitats, which encompass the entire range of UK habitats. This dataset is derived from the vector version of the Land Cover Map, which contains individual parcels of land cover and is the highest available spatial resolution. The 25m raster is the most detailed of the LCM2015 raster products both thematically and spatially, and it is used to derive the 1km products. LCM2015 is a land cover map of the UK which was produced at the Centre for Ecology & Hydrology by classifying satellite images from 2014 and 2015 into 21 Broad Habitat-based classes. LCM2015 consists of a range of raster and vector products and users should familiarise themselves with the full range (see related records, the CEH web site and the LCM2015 Dataset documentation) to select the product most suited to their needs. LCM2015 was produced at the Centre for Ecology & Hydrology by classifying satellite images from 2014 and 2015 into 21 Broad Habitat-based classes. It is one of a series of land cover maps, produced by UKCEH since 1990. They include versions in 1990, 2000, 2007, 2015, 2017, 2018 and 2019.
How would you define the boundaries of a town or city in England and Wales in 2016?
Maybe your definition would be based on its population size, geographic extent or where the industry and services are located. This was a question the ONS had to consider when creating a new statistical geography called Towns and Cities.
In reality, the ability to delimit the boundaries of a city or town is difficult!
Major Towns and Cities
The new statistical geography, Towns and Cities has been created based on population size and the extent of the built environment. It contains 112 towns and cities in England and Wales, where the residential and/or workday population > 75,000 people at the 2011 Census. It has been constructed using the existing Built-Up Area boundary set produced by Ordnance Survey in 2011.
This swipe map shows where the towns and cities and built-up areas are different. Just swipe the bar from left to right.
The blue polygons are the towns and cities and the purple polygons are the built-up areas.
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
An ARC GIS PRO shapefile mapping the turnpike roads in England and Wales for the 18th and early 19th century. The data includes details of the Turnpike Acts, years of operation, the quality of the road and the routes used by Mail coaches. The data forms the basis of the paper "Government, trusts, and the making of better roads in early nineteenth century England & Wales by Rosevear, Bogart & Shaw-Taylor.
The Land Cover Map of Great Britain 1990 (1km percentage target class, GB), is a raster digital dataset, providing a classification of land cover types into 25 classes, at a 1km resolution. The dataset consists of a set of 1km bands, each containing one of 25 target classes (or 'sub' classes). Each band of the dataset contains the percentage of the specified habitat class per 1km, derived from a higher resolution (25m) dataset. The map was produced using supervised maximum likelihood classifications of Landsat 5 Thematic Mapper satellite data. The 25 mapped classes include sea and inland waters, bare, suburban and urban areas, arable farmland, pastures and meadows, rough grass, grass heaths and moors, bracken, dwarf shrub heaths and moorland, scrub, deciduous and evergreen woodland, and upland and lowland bogs. It can potentially be used to plan, manage or monitor agriculture, ecology, conservation, forestry, environmental assessment, water supplies, urban spread, transport, telecommunications, recreation and mineral extraction. The map was produced in the early 1990s by a forerunner of the Centre for Ecology & Hydrology, the Institute of Terrestrial Ecology, at Monks Wood. Note: The bands in the dataset run from 1-26, not 0-25 as stated in the documentation. Hence '1' is unclassifed (not '0'), '2' is sea/estuary and so on.
This dataset consists of the vector version of the Land Cover Map 1990 (LCM1990) for Great Britain. The vector data set is the core LCM data set from which the full range of other LCM1990 products are derived. It provides a number of attributes including land cover at the target class level (given as an integer value and also as text), the number of pixels within the polygon classified as each land cover type and a probability value provided by the classification algorithm (for full details see the LCM1990 Dataset Documentation). The 21 target classes are based on the Joint Nature Conservation Committee (JNCC) Broad Habitats, which encompass the entire range of UK habitats. LCM1990 is a land cover map of the UK which was produced at the UK Centre for Ecology & Hydrology by classifying satellite images (mainly from 1989 and 1990) into 21 Broad Habitat-based classes. It is the first in a series of land cover maps for the UK, which also includes maps for 2000, 2007, 2015, 2017, 2018 and 2019. LCM1990 consists of a range of raster and vector products and users should familiarise themselves with the full range (see related records, the UKCEH web site and the LCM1990 Dataset documentation) to select the product most suited to their needs. This work was supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability.
https://www.openstreetmap.org/images/osm_logo.png" alt="" /> OpenStreetMap (openstreetmap.org) is a global collaborative mapping project, which offers maps and map data released with an open license, encouraging free re-use and re-distribution. The data is created by a large community of volunteers who use a variety of simple on-the-ground surveying techniques, and wiki-syle editing tools to collaborate as they create the maps, in a process which is open to everyone. The project originated in London, and an active community of mappers and developers are based here. Mapping work in London is ongoing (and you can help!) but the coverage is already good enough for many uses.
Browse the map of London on OpenStreetMap.org
The whole of England updated daily:
For more details of downloads available from OpenStreetMap, including downloading the whole planet, see 'planet.osm' on the wiki.
Download small areas of the map by bounding-box. For example this URL requests the data around Trafalgar Square:
http://api.openstreetmap.org/api/0.6/map?bbox=-0.13062,51.5065,-0.12557,51.50969
Data filtered by "tag". For example this URL returns all elements in London tagged shop=supermarket:
http://www.informationfreeway.org/api/0.6/*[shop=supermarket][bbox=-0.48,51.30,0.21,51.70]
The format of the data is a raw XML represention of all the elements making up the map. OpenStreetMap is composed of interconnected "nodes" and "ways" (and sometimes "relations") each with a set of name=value pairs called "tags". These classify and describe properties of the elements, and ultimately influence how they get drawn on the map. To understand more about tags, and different ways of working with this data format refer to the following pages on the OpenStreetMap wiki.
Rather than working with raw map data, you may prefer to embed maps from OpenStreetMap on your website with a simple bit of javascript. You can also present overlays of other data, in a manner very similar to working with google maps. In fact you can even use the google maps API to do this. See OSM on your own website for details and links to various javascript map libraries.
The OpenStreetMap project aims to attract large numbers of contributors who all chip in a little bit to help build the map. Although the map editing tools take a little while to learn, they are designed to be as simple as possible, so that everyone can get involved. This project offers an exciting means of allowing local London communities to take ownership of their part of the map.
Read about how to Get Involved and see the London page for details of OpenStreetMap community events.