The OpenStreetMap.org is a resource built by a community of volunteer mappers that contribute and maintain data about roads, trails, cafés, railway stations, as well as historical and current Irish boundaries, historical geographic features and much more, all over the world.
For more background on the project please see the OpenStreetMap Wiki or the project Homepage at https://www.openstreetmap.ie/
Other projects include :
- Irish townlands
Search Irish townlands by name, Civil Parish or County, over 60,800, many with Irish names & direct link to census - Irish boundary overlays
Townlands, Civil Parishes, Baronies, EDs, City wards, some PLUs & place names in Irish. (part of the OpenStreetMap project) - Irish maps 1900 to 1940s
A selection of old maps of Ireland as overlays. use the + icon to switch between layers. (part of the OpenStreetMap project) - HistOSM.org
A world wide map with about 650,000 historical geographic features so far