Archaeological Park of Dion, Archaeological site at Mount Olympus, Greece

The Archaeological Park of Dion is an open-air ancient Macedonian site at the northeastern foot of Mount Olympus, where sanctuaries, houses, public buildings, and bathhouses can be visited along marked paths. The structures come from different periods, giving a layered picture of what an ancient city looked like over time.

Dion grew during the classical period and became the main religious center of Macedonia in Hellenistic times, a place where kings and their armies stopped before campaigns. Under Roman rule the city stayed inhabited and active before it was eventually abandoned.

Dion was the religious centre of the Macedonian kingdom, where games in honour of Zeus and the nine Muses were held. King Archelaos I established these contests with athletic and musical competitions, and the kings received foreign guests there. Before setting out against the Persians, Alexander the Great sacrificed at Dion and held a nine-day festival.

The park covers 150 hectares, with about 50 hectares of the ancient urban area and 50 hectares of sanctuaries open to visitors; the rest is unexcavated. The archaeological museum lies half a kilometre west in the modern village of Dion, and the Dionysos mosaic is shown in a separate building behind it, viewed from a gallery above. Ground between the stone foundations is open and grassy, so sturdy shoes help.

Beneath the ground runs a network of ancient drainage channels that helped make the low, wet land at the foot of Olympus livable. Parts of this system are still visible on site and show how much engineering went into building a city in that location.