The Plutonium, located next to the Temple of Apollo, is the oldest local sanctuary and acted as a shrine to the god of the underworld; Pluto. It is a small cave, large enough for one person to enter, there are stairs leading down, where underground geological activity causes the emission of toxic carbon dioxide. There is also fast-flowing hot water, with a potent smelling gas. Since people died from the toxic gas, it was thought that the god of the underworld was sending this gas to kill people. In the early years, priests crawled over, holding they’re breath or by locating pockets of oxygen. This was seen as a miracle to the people and the priests were infused with superior powers and divine protection.