Dion is located 15 km SW of Katerini, 425 km to the north of Athens and 65 km to the north of Larissa. The village owes its name to the important sanctuary dedicated to Zeus (Dias, "of Zeus"), leader of the gods who dwelt on Mount Olympus; as recorded by Hesiod's Catalogue of Women, Thyia, daughter of Deucalion, bore Zeus two sons, Magnes and Makednos, eponym of Macedonians, who dwelt in Pieria at the foot of Mount Olympus. The ruins of the ancient city lie within the modern city's boundaries.
Dion was the "sacred place" of the Ancient Macedonians. From very ancient times, a large altar had been set up for the worship of Olympian Zeus and his daughters, the Muses, in a unique environment characterized by rich vegetation, towering trees, countless springs and a navigable river. In the 5th century BC, when the Macedonian state acquired great power and emerged onto the stage of history, brilliant athletic and theatrical contests, the "Olympian Games of Dion", were organized there. Their organization was overseen by the Macedonian kings themselves, who used the sanctuary of Zeus as a religious center for all Macedonians. A city was built adjacent to the sacred sites that acquired monumental form during the reigns of Alexander the Great's successors, and which experienced its second heyday during the reigns of 2nd- and 3rd-century AD Roman emperors who were fond of Alexander the Great. Dion's final important period was in the 4th and 5th centuries AD. It became extinct following major earthquake destructions.
The first mention of Dion in history comes from Thucydides, who reports that it was the first city reached by the Spartan general Brasidas after crossing from Thessaly into Macedon on his way through the realm of his ally Perdiccas II during his expedition against the Athenian colonies of Thrace in 424 BC. According to Diodorus Siculus, it was Archelaus I who, at the end of the 5th century BC, gave the city and its sanctuary their subsequent importance by instituting a nine-day festival that included athletic and dramatic competitions in honor of Zeus and the Muses. Litochoro is a town located at the base of Mount Olympus, on the western shore of the Thermaic Gulf. The first recorded mention of Litochoro is in an account of a visit by Saint Dionysius to Mount Olympus. The town is a popular destination for those wishing to climb Mount Olympus as almost all climbing routes begin to the southwest of the town.