The Maiden's Tower also known as Leander's Tower (Tower of Leandros) since the medieval Byzantine period, is a tower lying on a small islet located at the southern entrance of the Bosphorus strait 200 m (220 yd) from the coast of Üsküdar in Istanbul, Turkey. According to Turkish legend, a princess was locked in this tower to protect her from being bitten by a snake. Over the years the tower has been used as a customs station, lighthouse and a residence for retired naval officers.