KROO-a-han
The royal seat of Connacht in Co. Roscommon, from which Queen Medb rules and launches the Táin Bó Cúailnge.
Cruachan is Medb and Ailill's royal court, the political heart of Connacht in the same way Emain Macha is Ulster's. It is from here that Medb assembles her army and sets out on the cattle raid that becomes the Táin Bó Cúailnge, and the site is described in the texts as a place of gathering, feasting, and the reading of omens before the campaign begins.
The real archaeological complex at Rathcroghan — one of the largest unexcavated royal sites in Europe — includes a cave locally called "the gate to hell" (Oweynagat), which appears in early Irish literature as a place otherworldly beings and monsters emerge from, tying the site to more than just Medb's court alone.