Ordnance Survey – Great Britain's national mapping agency
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OS MasterMap Topography Layer is a detailed, intelligent, geographic database. It contains almost half a billion features from the built and natural landscape of Britain.
Detailed and surveyed to a high degree of accuracy, the Topography Layer is continually revised to incorporate changes to the urban and rural environment. It consists of nine themes: land area classifications; buildings; roads; tracks and paths; rail; water; terrain and height; heritage and antiquities; structures; and administrative boundaries.
The Topography Layer forms the foundation of OS MasterMap, and can be used in isolation or together with the Address Layer, Integrated Transport NetworkTM (ITN) Layer and Imagery Layer, to provide a consistent, analytical or reference framework.
Every feature within the Topography Layer has a unique identifier - defined as a TOID®. This ensures full integration across the other layers of OS MasterMap and enables the association of your own or third party data. Information can then be shared with assurance across different business applications and organisations that have a need for large-scale data.
