The Castalian Spring is situated next to the main road as you come on your way from the village of Arachova. At the sacred fountain of Delphi, the spring played a very important role in the cult of Apollo. Anyone who wanted to enter the sanctuary and consult Pythia had to purify themselves with the water of the Castalian Spring. The cleansing water of the spring gushed out of the slopes of the Phaedriades, which was called Iampia in antiquity. The archaic fountain, mentioned by Herodotus and many other poets in the first century BC, was replaced by another heavy construction entirely cut out of the natural porous bedrock. Water was collected in a long and narrow basin while seven metal spouts or jets and semi-columns made of stone adorned the basin's façade.