Two fountains, which were fed by the sacred spring, still survive. The archaicy 6th century BCE fountain house has a marble-lined basin surrounded by benches. There is also a Hellenistic or Roman fountain with niches hollowed in the rock to receive votive gifts. The Castalian Spring itself predates classical Delphi. The ancient guardian of the spring was the serpent Python, which was killed by Apollo in its lair beside the spring.
This spring in a ravine once provided drinking and washing water for the priestesses who pronounced the oracles here. The spectres of three women are said to sometimes wander the area, which is now closed off to visitors - supposedly because of falling rocks. However, a channel filled with water running from the spring comes out to the pathway.
In Castalia, Ohio, named after the famed site, the Blue Hole limestone configurations were tourist attractions for many years and are now fish hatcheries. Waters in the blue holes are of a constant temperature and never freeze over despite northern Ohio's cold temperatures. The water which averages 30,000 gallons an hour was first used to supply a local mill.