At the northeastern end of Kouphonesi, opposite the Marmara islet, and at a small distance from the beach, excavations have brought to light a well preserved stone-built theatre; the cavea had twelve rows of seats and a capacity of c. 1000 persons. Part of the cavea and the stone seats are not preserved today. The orchestra, almost semicircular in shape, was paved with clay slabs. The stage building (measuring 20 x 19 m.) is destroyed in the western part, but the eastern part, the paraskenion, the logeion, the hyposkenion and the east parodos, which had a tholos roof are preserved. It seems that the theatre was severely looted and destroyed by fanatic Christians in the 4th century A.D.
Source: www.incrediblecrete.gr