Mystras (Greek: Μυστράς, Μυζηθράς, Myzithras in the chronicle of Morea) was a fortified town in Morea (the medieval Peloponnese), on Mt. Taygetos, near ancient Sparta. In the 14th and 15th centuries, it served as the capital of the Byzantine Despotate of the Morea, experiencing a period of prosperity and cultural flowering. The site remained inhabited throughout the Ottoman period, when it was mistaken by Western travellers for ancient Sparta. It was abandoned in the 1830s, when the new town of Sparti was built, approximately eight kilometres to the east.

http://en.wikipedia.org/wiki/Mystras