They date back to the time when the region was a part of the Roman Empire and the settlement was called Odessos. The preserved parts of the building give grounds to believe that the Roman Baths were one of the largest buildings in the eastern part of the Empire and a proof for the wealth and importance of the town.
The height of the domed constructions is supposed to have been no less than 20 m. The building was erected in the second half of the 2nd century on an area of about 7 000 square metres and was in use until the end of the 3rd century. Its thick walls were built after a specific technology alternating layers of stone blocks with 5-6 layers of solid clay bricks.

The inside stairs and the arches over the doors are made of large stone blocks. In some places one can still see fragments of magnificent mosaics. They, together with numerous decorative fragments of marble, the stone columns and capitals are indicative of the ornate decoration of the building.
Passing through the spacious halls that formed a natural barrier to the cold air, the visitors entered a large hall called balestra. With its area of 840 square metres it was a unique centre where the citizens of ancient Odessos got together to discuss important issues of public life. Even today people are curious to learn how its heating system was designed and worked. It included a double floor and special hollows through which hot air reached up to the roof of the Baths. A host of little shops, game rooms, halls for bathing in cold, warm and hot water, rest rooms - the visitors today can imagine what a busy life was bubbling in the ancient Roman Baths.