An ancient settlement located on the hill just southwest of the village of Beyköy, now a detached neighborhood of Kepsut farther to the west. J. Arthur R. Munro, traveling through the area, identified the site as a Greek town and located some inscriptions from the Roman period and Late Antiquity. This convinced him that ancient Hadrianoutherai should be sought here, at Beyköy, and not at Kepsut or at Çayırhisar on the southeastern edge of Balıkesir. The latter location is favored for Hadrianoutherai today, but the evidence for some sort of ancient town by Beyköy remains.
J. Arthur R. Munro, "Gleanings from Mysia," Journal of Hellenic Studies 21 (1901) 229-237.