The castle crowns the hill of Mystras. It was first built by the Franks and later altered by the Byzantines and the Ottomans. Long and narrow – almost 170 metres – it has two lines of walls: the inner one with the commander's tower-house, the outer one with a round tower.
On one side the walls drop straight into the cliffs. It is the steepest climb of the visit, but the reward is a sweeping view over the Laconian valley.