The ancient city occupies a natural mound to the NW of the village of Petres, in the region of Florina. Its total area reached 15-20 hectares and was protected by a fortification wall built of poros stone. The enclosed area included houses, and public buildings erected in a free layout, separated by streets, 2.5 m. wide. The city was founded in the 3rd century B.C. by Antigonos Gonatas, it flourished in the 2nd century B.C. and it ceased to exist in the 1st century B.C. It was again inhabited in the Roman period, but it moved to a different site.