Ireland is a small country, divided into Northern Ireland, which politically belongs to the United Kingdom, and Southern Ireland, the Republic of Ireland. Another way to divide the island are the 26 counties of Ireland and 5 counties of Northern Ireland. For statistical reasons they are grouped into eight regions. Historical Ireland was divided into four provinces, cúige, which were Leinster, Munster, Connacht, and Ulster.
Unfortunately those political stuctures are not very usefull for our website, as they are either too coarse or too fine grained. So we decided to group the listed locations by their geological background. As the geological situation is rather complicated and this is overview is very brief, there may be some minor inconsistencies.