Castalia

Castalia, a stream issuing from a cleft in the Phaedriades, the cliffs at the base of Mount Parnassus, at Delphi in Greece. It was venerated as the haunt of Apollo and the Muses, and so came to be looked upon as a source of poetic inspiration. "Castalius" is a classical epithet for anything connected with Apollo, and the Muses are styled "Castalides." In modern times the spring bears the name of St. John.