Mystras is a late Byzantine city on the slopes of Mount Taygetos, about 40 km north of Gythio — a UNESCO site with churches, the Palace of the Despots, and frescoes from the 13th to 15th centuries. An early morning departure around 8 AM is essential in summer as there is no shade; the visit takes 2-3 hours, after which you can stop in Sparta for lunch. Entrance fee is 12 EUR.