Lia Fáil
The Lia Fáil is one of the many alternate names for the Stone of Destiny. ("Rock of Ages")
Real World Background
The Lia Fáil is the name of the Stone of Destiny kept at Tara in Irish myth. According to legend, it would scream aloud when the rightful High King of Ireland stood upon it.
According to legend, the Lia Fáil was brought to Ireland by the Tuatha de Danaan (the ancient gods of Ireland, who later became the faerie-folk) as one of four treasures from their four great cities; the Lia Fáil came from the city of Falias in the north. (The other three treasures were a cauldron, a spear, and a sword.) The legendary Irish king Conn of the Hundred Battles discovered it, apparently the first High King of Ireland to be acknowledged as such by the Stone.
Later stories, after the Christianization of Ireland, identify the Lia Fáil with the stone that Jacob used for a pillow at Bethel, and brought to Ireland by the prophet Jeremiah, as in Shari's tales.