Omphalos Stone
The Omphalos Stone, "omphalos" meaning "navel," is an ancient artifact and one of the most sacred in the entire Achaean Empire. It is said to aid the Pythia in her prophetic visions and allow contact with the divine, including the gods themselves.
History
When Kronos planned to devour his children before one could slay him, Rhea swaddled a stone in clothing and presented it to him, pretending it to be his son, Zeus. Believing her, Kronos swallowed the stone instead of Zeus, which led to his foretold defeat. The stone was extracted and placed by Zeus at the "center of the world." Zeus deemed the center of the world to be the site where the city Krisa stands today, and the stone became known as the Omphalos Stone.
Current Location
A large stone is displayed within the temple at Krisa, but a smaller stone is claimed to be brought out alongside the Pythia during oracle visitations. Many visitors believe this may be the real omphalos stone, while the one on display is for purposes of worship by the common people. If true, the real omphalos is as heavily protected as the Pythia herself.