One of the great cities you've probably never heard of, Mistra was the capital of the Byzantine despotate of Morea in the Peloponnesus. Very near Classical Sparta, it was the most important possession of the decaying empire outside of Constantinople after the suicidal civil wars of the fourteenth century. The heir to the throne was usually made the Despot of Morea, a sort of Prince of Wales title for the Byzantines. In the empire's waning hours, it became a center for learning and the preservation of Greek literature and philosophy that would decisively influence the developing humanist movements in Renaissance Italy. Without Mistra, the West probably loses the better part of its classical Greek heritage.
A British tourist recently visited Mistra and took a magnificent series of pictures, along with some useful (if leavened with a stray if understandable obscenity) commentary about the area. Modern Sparta also appears, along with a nice shot of the Eurotas Valley. Enjoy.
[Via the Ellopos blog. Caution for fellow papists--Elpenor, the operator of the blog, is an Orthodox with a serious, Mount Tabor-sized bug about Catholicism. While a useful website otherwise, consider yourself warned. And I definitely haven't searched every nook and cranny, either.]