In North Mayo off Downpatrick Head there is a sea stack known as Dun Briste.
According to an old local legend, it is associated with the conflict between Saint Patrick and the pagan chieftain or pagan god named Crom Dubh, who refused to convert to Christianity and attempted to throw Patrick into his everlasting fire.
Patrick picked up a stone from the ground and scratched a cross on it, then he threw the stone into that fire. The fire collapsed into the sea forming a blowhole known as Poll a Sean Tine, meaning ‘The hole of the ancient fire’.
Crom Dubh retreated into his fortress on the top of the cliff, but Patrick struck the ground with his crozier, the stack and his fort were separated from the mainland, leaving Crom Dubh isolated on the stack and devoured by midges.