The waters of the Castalian Spring at the gorge of the Phaedriades, hide a story about a nymph, the daughter of Acheloos, who wanted to escape from Apollo, god of the sun, and thus transformed herself into crystal water. The priests of Delphi built a fountain to channel this water and placed lion Heads on the bronze faucets, to offer purification to the faithful before they passed over the threshold of the temple of Apollo.