Island of Ireland map divided by counties

Geopolitically, Ireland is divided between the Republic of Ireland (officially named Ireland), which covers five-sixths of the island, and Northern Ireland, which is part of the United Kingdom. But there are plenty of cases where it makes sense to represent the island without those geopolical borders and display the historical counties.

We used a custom JSON source to build this map of Ireland (source) divided by historical counties and added some markers to populate the map.