The great baths of Dion were constructed in the last decades of the 2nd century AD and were in use until the second half of the 3rd century AD, when a powerful earthquake destroyed the building. They were part of a complex organised around an open space, nowadays shaded with high trees. This complex included the odeion, a small roofed theatre, and the public toilets along the central road.

A narrow forecourt was the entrance to the baths at the east side of the building. It led to a spacious reception hall with mosaic floors, where portraits of eminent men from the local community, such as the philosopher Herennianons were displayed. South to the entrance were the disrobing room and the quarters for the lukewarm and hot baths. The floor of the heated areas was set on a framework of short square columns arranged so as to create a basement, the hypocaust.