Rathcroghan is a complex of archaeological sites near Tulsk in County Roscommon. It is identified as the site of Cruachan, the traditional capital of the Connachta, the princes of Connaught. The name is form the Irish language, in which it is known as Ráth Cruachan, meaning 'Ringfort of Cruachan'.
The Rathcroghan Complex (Crúachan Aí) is a unique archaeological landscape with many references found in early Irish mediæval manuscripts. A cave within the complex was even reputed to be a gateway to the otherworld. (Read more)