Some 4km northeast of Kızkalesi at Ayaş, are the extensive remains of ancient Elaiussa-Sebaste, a city dating back to the early Roman period and perhaps even to the Hittite era. Important structures on the left (west) side include a 2300-seat hilltop theatre , the remains of a Byzantine basilica , a Roman temple with floor mosaics of fish and dolphins, and a total-immersion cruciform baptistery . The ruins of a Byzantine palace are on the eastern side of the highway.
