The 25 x 30 meter Bouleuterion is dated to the 1st century A.D. according to the architectural elements and decorations. For a long time it was assumed that the building was a temple of Serapis. The excavations in the building brought to light the remains of the semicircular cavea as well as Greek inscriptions on the inner wall and Latin inscriptions on the outer wall.

On the north-facing 23 square metre exterior wall of the Bouleuterion, a price list of the Emperor Diocletian and the instructions for its implementation in Latin are engraved. The price list details the name and price of 200 products sold there during this period.