At the top of the hill of Old Pyli you will notice the remains of the Castle. The entrance gate was built around the end of the 11th century AD or at the beginning of the 12th century by a byzantine administrator. The use of bricks is unique in the whole of the Dodecanese. During the 15th century and under the threat of a Turkish invasion the Castle was often used as a refuge for the people of the area as well as the population of the city of Kos. By 1461 it was the only manned castle left and fortifications were improved while ammunition was accumulated. The castle fell in the hands of the Turks in 1523. The area was abandoned in the beginning of the 19th century for unknown reasons.