Covering an area of 1.500.000 m², Dion Archaeological Site consists of a fortified city that spreads on 360.000 m², surrounded by cult areas. The ancient city was inhabited continuously from the Classical period to Early Christian times. Private residences, public buildings, shops and a large number of workshops erected in building blocks surrounded by streets, were discovered in successive archaeological layers. Dion was built in the 2nd century B.C. on a flat terrain, at a distance of approximately 1.5 km from the sea and it was connected to it through the River Vafira.

The walled part of city, almost square, was built according to the Hippodamian system and was a typical example of model city planning and expertise found in the times of Alexander the Great. In their majority, the archaeological findings available to date, can be traced to Roman times and the post Byzantine period: the small amount of backfilling as well as continuous habitation wiped out the traces of former archaeological periods apart from a few exceptions. The current state of the archaeological site corresponds mostly to the Roman period.

The central road of 670 meters that crosses the city from north to south, dates back to the imperial era, it is paved with large Conglomerate slabs, and its design matches of course the Classic-Hellenistic urban structure. The original grid also comprises of secondary roads vertical and parallel to the main road, part of a Hippodamian Plan. Stores, luxurious residences, public baths (thermae), workshops and public sanitary facilities (Vespasennes) were discovered underneath the city blocks that are formed. Constructions of the 2nd and the 3rd century AD attest to the citizens wealth and affluence. The large public baths (thermae) – a truly impressive building complex that dates back to 200 AD- are located on the southern edge of the ancient city.αποκαλύφτηκαν

Dionysus’ Manor House (“the Villa of Dionysus”), which was discovered in the eastern sector, was named after a large mosaic composition, depicting the god that covers the floor of the Banquet Hall. Dion Sanctuaries, Hellenistic and Roman Theaters as well as the Stadium were discovered outside the city walls. There is no doubt that the regular shape (square) of the city was dictated by the lowland terrain, but, as it has been suggested, it is also quite likely that both the town-plan and the fortifications of Dion called upon the experience gained by city builders of the time from the new cities founded by Alexander the Great and his successors in the lands of Asia.

Olympian Zeus, after whom the city was named, held a dominant position among the Gods worshiped at Dion. Many stone sculptures (“stelae) bearing inscriptions relating to alliance treaties, the settlement of border disputes, official decrees etc. were found at the god’s temple. The Sanctuary of Demeter to the south, just outside the city walls and the gate at the end of the main road of the city, is the earliest Macedonian Sanctuary known to date. The monument dates from the late 6th c B.C. to the early 4th c A.D. A sanctuary devoted to the cult of the Egyptian Gods, Sarapis, Isis and Anubis was discovered to the east of the Sanctuary of Demeter. There is also the small temple of Aphrodite Hypolympidia (Aphrodite worshiped below Mount Olympus) in this same sanctuary.
The Hellenistic theatre of Dion, which lies outside the walls, was built in the reign of Philip V (221 – 179 B.C.). The Roman Theater, dating from 2nd c A.D. was discovered to the south-east of the Hellenistic structure. The cemetery of Dion extends mainly to the south and the east of the city. The funeral monuments date from the 5th c B.C. to the 5th c A.D.