The Maiden's Tower also known as Leander’s Tower ( Tower of Leandros) since the medieval Byzantine period, is a tower on a small islet at the southern entrance of the Bosphorus strait near Uskudar. The tower was originally built by the Athenian general Alcibiades in 408 BC as a custom station for ships coming from the Black Sea. It was later rebuilt and used as a defense tower by the Byzantine emperors, who connected it to the Asian shore with a chain to prevent enemy ships from entering the Bosphorus. During the Ottoman conquest of Constantinople in 1453, the tower was destroyed and then reconstructed by Sultan Mehmed II. It served as a lighthouse, a quarantine station, and a military base throughout the Ottoman era.