The Palace of the Despots fills one side of the main square of the Upper Town of Mystras. It is a complex of two wings from different periods: a fortress-like Frankish wing and the main residence of about 1350–1400, home of the Kantakouzenos and Palaiologos despots.
Its highlight is the Throne Hall, a vast room of 36 by 10 metres with Gothic arched windows, round skylights and eight fireplaces. Under the Ottomans the square was used as a market. It is one of the rare Byzantine palaces to survive.