Built in the 2nd century BC, the Bouleuterion is almost square at 16.90 x 17.70 metres. The conference room with a capacity of 400 persons is divided into two sections (kerkides) by a central staircase.

At the beginning of the 14th century, towards the end of the Byzantine period, a new fortress was built between Acropolis and Stoa to protect it from threatening Ottoman invasions. The fortress wall was pulled through the middle of the Bouleuterion in disregard of the old building substance. Soon after the inevitable conquest by the Ottomans in the 15th century, the city was abandoned and the inhabitants moved to Torbalı.