Cruachan is located in Co. Roscommon, Ireland. It has a few different names, including Rathcroghan, meaning “ringfort of Cruachan”. Because it contains the Gates of Hell and many well-known characters in Irish mythology interacted with the place, it is a significant mythological site for Ireland.
Cruachan was one of the six most important royal sites in ancient Ireland, and was the capital of Connaught. Becaise of this, it was also the royal seat of Queen Medb. Cruachan is one of the possible sites where she was buried. The other possible sites include a stone cairn outside Sligo town and Knockma in Co. Galway.
Heroes and The Irish Underworld
Cruachan covers a massive area, and Uaimh na gCait, Oweynagat, the Cave of the Cats, is located there. This cave appears in many Irish tales.
In the mythical story of Bricriu’s feast, Bricriu challenged three champions to a competition to prove their worthiness. In one of the competitions, he released three cats from Oweynegat. Two of the champions fled and hid. The third champion, Cu Chulainn, held his ground, proving himself the worthiest.
In another story featuring Cruachan, the courageous hero Nera speaks with a dead man on Samhain night. He sees the future. The cave appears in the tale as an underground fairy fort. In mythology, it is one of the most important portals to the Irish otherworld.
Early Christian writers described Oweynagat as “the Gates of Hell” due to the amount of demonic and ghostly traffic it received. The Cave was especially active at Samhain, a significant pagan festival. Today, Halloween celebrations have replaced Samhain.
Finally, Cruachan was also home to the great phantom war Queen, the Morrigan. The Morrigan of ancient Ireland was three sisters named Bodhbh, Macha, and Anand. Together, they comprised the goddess of war and fate.
In the epic poem, Tain Bo Cuailnge, the Morrigan intervenes as Cu Chulainn defends Ulster. She appears as a hooded crow, famously landing on the epic hero’s shoulder. It is from the Gates of Hell that she drives forth on her chariot, led by her one-legged chestnut horse.
Mythical Irish Beasts by Mark Joyce