Search the PRONI Historical Maps viewer
Search and browse a range of historical Ordnance Survey of Northern Ireland (OSNI) maps and find information on sites, buildings and landmarks of historical interest.
Before you start
PRONI Historical Maps viewer can be used to search and browse seven historical OSNI maps and four modern basemaps (including aerial imagery).
The viewer displays county, parish and townland boundaries and includes information on sites, buildings and landmarks of historical interest.
A variety of tools and 'widgets' allow you to search and browse the maps, compare one map with another, and find various points of historical interest.
Find summary guidance on using the application below, or open the 'Help' widget in the Historical Maps viewer for a detailed description of to use the various functions.
There have been a number of queries about an error message that appears when the Historical Maps Viewer is opened using Internet Explorer 11. Use of an up-to-date Internet Browser such as Microsoft Edge (Internet Explorer’s replacement), Google Chrome, Mozilla Firefox or Safari should resolve this issue.
The search text box (located at the top left hand side of the screen) enables you to search by townland, parish or town/ city name; or using modern postal address.
You can browse the map or navigate to a particular area by using the plus and minus buttons on the application; using the rollerball on your mouse, or by 'clicking and dragging' using your mouse. To find out information about your area of interest (the townland name, parish and county), press on a particular point on the map.
Various functions can be performed using the widgets (icons) which are located in a row at the top right hand side of your screen. Widget functions are summarised below.
Help using the Historical Maps viewer:
The Help widget has a guide on how to use the PRONI Historical Maps viewer and a link to a PDF version of this guidance which can be downloaded for reference.
Map layers and datasets:
The Basemap Gallery widget allows you to choose from a selection of four basemaps. The application defaults to the OSNI Basemap, which is generated using a range of OSNI map products such as 1:50,000 Vector and Largescale data.
Layer List Widget
The Layer List widget shows each of the optional layers which can be switched on or off. Layers include seven historical Ordnance Survey maps (covering the years 1832 - 1986); and a range of datasets (including county, townland and parish boundaries; and sites, landmarks and buildings of historical interest).
The Swipe widget provides a vertical bar on your screen which can be dragged back and forth across the screen to compare one map layer with another. These layers can be selected using the Layer List widget.
The Info Widget outlines the maps and datasets available on the PRONI Historical Maps viewer.
The Legend Widget details the meaning of the various outlines and symbols used in the Maps viewer.
The Bookmark Widget allows you to name and store links to specific areas, so you can easily navigate to a specific point during future visits (using the same PC/ tablet).
Survey Date Widget
The Survey Date Widget allows you to identify the PRONI references for each historic Ordnance Survey map on the application at a specific point.