We can come across her on Delphi which was dedicated to Apollo God.
Pythia was giving the predictions of oracles. She was the one who was communicating with Gods transmitting the messages and the answers to the people.
She was elected among the Delphis' Virgins of noble origin.
Before she was predicting, Pythia was cleaning her body, drinking water from Castalia source and consequently she was chewing daphne leafs.
That's how she was coming in a high spiritual state of mind so to reply the questions of the mortals.