The origins of the sanctuary, which is known for its nationwide radiation, go back to the Bronze Age (2600-1200). Initially the sanctuary was outdoor and worshiped the Great Goddess, goddess of fertility and welfare, which was later replaced by the worship of the same god. The priests said oracles listening to the sounds of tripods were around the beech, the sacred oak of Zeus. To his credit was the NAIA, renowned Panhellenic games. In the 4th century. began building the first church, the “Holy House”. Yet it was restored radically in 3rd century. on King Pyrrhus. Then built the Prytaneion, the parliament and the Theatre, which is one of the largest ancient theaters (about 17,000 jobs).