OS MasterMap® Topography Layer

Previously recorded as seperate Datasets - MMLine - MMArea - MMAnno - MMLineBlk

OS Published Data:
For INSPIRE/GEMINI2 compliant metadata please see here -
This page is non compliant, but created to help with use within HCC:

OS MasterMap® Topography Layer
Alternative Title
MMLine MMArea MMAnno, MM, mastermap
The OS MasterMap Topography Layer is a large-scale digital database of the detailed surface features on the landscape, with relative positions and elevations of every town, manor, parish, or tract of land mapped to minute detail. This highly accurate, flexible resource covers some 400 million man-made and natural features, from fields to pillar boxes, each with its own unique identifier or TOID® for easy reference. It is broken down into nine themes to make it easier to access the data; roads, tracks and paths; land; buildings; water; rail; height; heritage; structures; and administrative boundaries. There is the choice of a single theme, a combination of themes or all of the above. When overlaid with other OS MasterMap layers or the customer's own data, it will provide a clear picture of what's on the ground. The Topography Layer helps in the planning and management of land and property by enabling users to visualise the context of any feature or site, to pinpoint individual properties and precise sites when a high level of detail is required, and to assess the impact of a proposed development effectively and efficiently. It is data association that makes OS MasterMap intelligent. It enables organisations to link their own data to that of the digital map. By associating their data to the OS MasterMap features, organisations are then able to analyse a richer database, and can search and query using their own data fields as well as the attributes provided by OS MasterMap.
Topic Category
Keyword Value: Topography
Originating Controlled Vocabulary: Integrated Public Sector Vocabulary (IPSV)

Keyword Value:Buildings
Originating Controlled Vocabulary: GEMET - INSPIRE Spatial Data Themes (GEMET)
Originating Controlled Vocabulary Citation: 2008-12-05
Temporal Extent
- /2013-03-28
Dataset Reference Date
Date: 2013-05-16
Date Type: Publication
Bounding coordinates
West Bounding Longitude: -0.76
East Bounding Longitude: 0.22
North Bounding Latitude: 52.10
South Bounding Latitude: 51.58
Hertfordshire County
Spatial reference system
National Grid of Great Britain
Spatial Resolution
Resource Locator
Maps and Geographic Information - Hertfordshire County Council:
Data Format
Name of Format: ESRI/Shape file, ESRI/SDE
Version of the Format:
Responsible Organisation
Hertfordshire County Council - Corporate GIS Team
Role: Distributor
Update frequency
Limitations on Public Access
Copyright Controlled. Use is subject to licence.
Use Constraints
Licensed under the Public Sector Mapping Agreement;

You must use the appropriate Copyright Acknowledgement;

For internal use:
For external use:
For Publicly Available Electronic Copies the following must also be added:
  • The HCC Watermark;
  • The phrase: "Use of this data is subject to terms and conditions." set out in a legible font and conspicuous position must form a clear hyperlink to

This data is supplied without guarantee or any warranty as to the accuracy, currency or completeness, and is provided as is, excluding any warranties of any kind, either express or implied, to the fullest extent permitted by law, including (but not limited to) satisfactory quality or fitness for a particular purpose.
Additional information source
MasterMap Topography Information on the Ordnance Survey Website:
MasterMap Topography User Guide on the Ordnance Survey Website:
Unique Resource Identifier
Code: Mastermap_topo
Codespace: OS
Metadata update date
Metadata Point of Contact
Hertfordshire County Council - Corporate GIS Team
More Information


Dataset: R:\GIS\geodata\os\mastermap\Mastermap_topo
Viewable In All Viewers, but not queryable.