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GIS at UCD and on the Web: Maps with Contours

UCD Library GIS Guide

OSi Discovery Series Vector Tiles

Sample image of Discovery contour layer data in Irish Grid projection overlaid on Discovery mapping from MapGenie. Resolution: Contours: vertical interval of 10m. 

Discovery Base Mapping Data and Discovery Contour Data is available in vector format. Please complete and submit the application form OSi Mapping Request Form: Discovery Vector and Contour Vector Tiles to request this data. 


Discovery Tiles Index

Discovery Series data at 1:50,000 scale is available in vector format in Irish Grid projection for the Republic of Ireland.

The Contour Lines data in Irish Grid projection for Discovery mapping is also available as a separate layer. 

This dataset consists of 10 metre contours for the Republic of Ireland.

Click on the Discovery Index above to find the tile (s) you need. Each of the 251 tiles which cover the country are represented on the squares above. Tiles for your area of interest are available to obtain by request by completing the online application form above.

For each square shown above two tiles can be supplied, e.g. 1838_C for the contour lines layer and 1838_D for the Discovery vector layer. Don't forget to ask for both!


Here's an enlarged extract from the index which shows you how to find the right tile number:

Use the Eastings along the bottom of the grid, followed by the Northings along the side to get your tile number.

Read the number on the vertical line at the left hand side of the square you need. Next, read the number on the horizontal line below the square you need. In this example above the square coloured blue is tile number 2408


View Contours via GeoHive

Irish maps which show contour lines

A contour is a line on a map that connects points of equal elevation and is usually based on height above sea level.


Extract from Military Series Map - Howth Sheet 32/23 S.W. showing contours at intervals of 50, 100, 200, etc.,feet


Index to the Military Maps GSGS 3906. Online seamless access to the GSGS 3906 series is available via OpenStreetMap.These military maps were reproduced in the 1940s in Great Britain by the War Office at a scale of 1:25,000 but derived from 1:10,560 county maps published between 1895 - 1918. Most sheets are composites of four six inch maps, photographically reduced with the contours overprinted.

List of the Military Maps GSGS 3906 Series These maps are held in Richview Library and also in the GPEP Map Library


Extract from Discovery Series map showing contour lines along the Kerry Way


Discovery Series maps are published at a scale of 1:50,000.

Contours are shown at intervals of 10 and 50 metres. 

Altitudes are given in metres above Mean Sea Level at Malin Head, Co Donegal.

These maps also show spot heights.

To obtain free Discovery mapping tiles in vector format please refer to the Free OSi Data page


Extract from OS 6inch map showing Glendalough

1:10,560 Ordnance Survey maps (six inch to 1 mile). Maps at this scale are available for the whole of Ireland but have not been updated since the 1930s. For more information about this series see Trinity Map Library's guide. Altitudes are given in feet and contours are shown at intervals of 50, 100, 200, etc. Some editions show the contour lines in red.


Extract from Dublin sheet 12 @ five feet to one mile 1847 map showing Temple Street West


Dublin 5 feet to 1 mile maps These maps which show contour lines are included in the Ordnance Survey Ireland (OSi) 19th Century Historical Maps online digital collection and are therefore available to view and take prints from. Two editions were published - one in 1843 and the other in 1864.There are 33 maps in each edition covering the area between the canals. 

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