Sidhe

In Irish mythology, the Sidhe are the fairy folk, quite distinct from humankind, who live beneath the earthen mounds. There are a number of different types of Sidhe: the Sluagh Sidhe can fly through the air and shift shape at will, the Sidhe who walk the earth at dusk and the guardian Sidhe of the lakes of both Ireland and Scotland.

After their defeat by the Mils (the Celts), the Tuatha de Danaan went to join the Sidhe beneath the earth.