Public Record Office of Northern Ireland (PRONI) - Historical Maps Viewer

The PRONI - Historical Maps Viewer can be used to search and browse seven historical Ordnance Survey of Northern Ireland maps and four modern base maps (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' enable you to search and browse the maps, compare one map with another, and find various points of historical interest. The historical OSNI maps available are from the 6 inch County Series mapping; and latterly the Irish Grid. They cover the six counties of present-day Northern Ireland: counties Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone and include:
• Edition 1 (1832 – 1846)
• Edition 2 (1846 – 1862)
• Edition 3 (1900 - 1907)
• Edition 4 (1905 - 1957)
• Edition 5 (1919 – 1963)
• 6” Irish Grid (1952-1969)
• 1:10,000 metric Irish Grid (1957-1986) New