Kelefas fortress is located on the mount Taygetos crowning the bay of Oitylo. It was built in 1670 by the Turks so as to control the Maniots. In 1685, The Venetians conquered the fortress and performed fortification works making it one of the most powerful in the area. In 1715 it fell once again in the hands of the Turks, which they abandoned later. Its walls are thin, simply constructed, and it has five circular towers and 58 canons. Today is in bad condition, but you can visit it for free.