The Anatolian Castle is located in Beykoz on the Asian side of Turkey and at the narrowest point in the Bosphorus. It was built in 1395 by Bayezid I, and consists of a central castle and outer walls. After the conquest of Istanbul, the castle lost much of its strategic importance and was converted into a military hospital. With the passage of time the area around the castle became stable, and today the old houses and palaces are spread among the ruins of the castle, and during the restoration work that lasted from 1991-1993, the castle was converted into an open museum.