The most well-known ancient city of Olympus was Dion, build on the eastern foot of the mountain, four kilometres in a straight line from the peak, where the gods lived. In this holy Macedonian city stood the magnificent temple of Olympian Zeus. In 334 BC, Alexander the Great made a sacrifice in this temple, before departing with 30000 Macedonians for his grand campaign in Asia. In this holy city, the Macedonian king erected 26 bronze statues, works of the famous sculptor Lyssipos, depicting the fallen companions at the battle of Granicus. The nine-day festival in honour of Zeus, the Olympiads and Pierid Muses (one day for each Muse) was held in the shadow of the mountain. In the city’s theatre, the great playwright Euripides would present his tragedies. During Roman rule, the city flourished greatly, a tendency that continued into the Byzantine era. Archaeological excavations, under the direction of Dimitris Pantermalis, professor of archaeology at AUTH, brought great findings to light, which highlighted the breadth and richness of the city. The ancient city had broad and spacious paved roads running through it, and a sturdy wall, constructed in the 4th century BC, encompassing it. The wall underwent multiple repairs up until the Byzantine period. Some of the most notable buildings investigates are the Roman baths, the conservatory and mansion of Dionysus, a residence with intricate floor mosaics etc. South of the city, outside the wall, several sanctuaries of Dion were found. These were centres of worship for the Macedonians. Namely, these are: The temple of Olympian Zeus, near the Roman theatre, the sanctuary of Demeter, and the sanctuary of Isis. In the sanctuary of the Egyptian goddess, several statues were found still standing on their pedestals including that of Aphrodite “Hypolympidia” – the goddess worshipped under Olympus. Also discovered were the ruins of two theatres, where plays, games and other events were held. On dates to the Hellenistic period and had clay seating, while the other was built in the 2nd century BC, during the Roman era. In the older theatre, rebuilt with wooden seating, the events of the Olympus Festival are hosted. A short distance from the western wall, a brilliant Macedonian tomb was discovered, with an arched roof and decorations that depict warriors of horseback and busts of lions. It was built around 300 BC and belonged to a Macedonian general of Pieria. The Apostle Paul passed through the region of Olympus in the first century AD, spreading Christianity. Great churches were built atop the ancient constructions, which demonstrate the growth of the religion during the early Christian period. One of the biggest early Christian basilicas, from the 5th century, was excavated at the Dion archaeological site. The rich findings of the Dion excavation (marble and copper sculptures, mosaics, vases, jewellery etc.) are housed in the two-floor archaeological museum of Dion. Among the wondrous exhibits, the Hydraulis of Dion is of particular note. It is an ancient musical instrument that dates back to the 1st century BC. Only the bronze flutes and plates that held them in place are preserved. It is the oldest musical instrument preserved that is a direct progenitor to the western ecclesiastical organ. Archaeological findings from the broader area of Dion and Olympus are also hosted in the museum. In the museum’s basement, there is an educational exhibition for primary to tertiary students that focuses on the daily life of the ancient inhabitants of Dion.