The Altis, the walled sacred precinct at the heart of Olympia, held the sanctuary’s most important religious buildings. Chief among them was the Temple of Zeus, built in the 5th century BC to house Pheidias’ colossal gold-and-ivory statue of the god, once counted among the Seven Wonders of the Ancient World; its surviving columns and pediment sculptures (now largely in the Olympia Museum) still convey the temple’s original scale. Other structures within the Altis included the Heraion, an early Doric temple to Hera and one of the oldest in Greece; the Prytaneion, seat of the sanctuary’s officials, where the sacred flame was kept burning; the Philippeion, a circular monument built by Philip II of Macedon to commemorate his victory at Chaeronea; and the Pelopeion, a shrine to the hero Pelops, mythical founder of the Olympic Games. [Editor’s note: the original site had only brief photo labels for this page. This paragraph was drafted as a placeholder and should be reviewed/expanded by Dr. Siegel.]