Rathcroghan is a complex of archaeological sites near
Tulsk in
County Roscommon, Ireland. It is identified as the site of
Cruachan, the traditional capital of the
Connachta, a term used to describe the prehistoric and early historic rulers of the western territory.The Rathcroghan Complex (Crúachan Aí) is a unique archaeological landscape with many references found in early Irish medieval manuscripts.