Platamon Castle sits on a rock above the beach town of Platamonas, about 40 km south of Katerini on the main Athens–Thessaloniki road. It was built by the Crusaders after 1204, following the sack of Constantinople and the establishment of the Latin Empire. The castle controlled the Tempe Pass — the narrow coastal corridor between Olympus and the sea where the only viable road south from Macedonia runs — and has changed hands between Crusaders, Byzantines, and Ottomans over its history.
The castle is well preserved. The main tower (keep) stands nearly intact, and the circuit walls and gatehouse are largely complete. The site is signposted from the main road and the climb up from the car park takes about 15 minutes. Views from the keep over the beach and the sea are excellent, and on clear days Mount Olympus is visible to the north. The adjacent beach of Platamonas is a decent stopping point for a swim. The castle hosts an annual summer festival of theatre and music; the ancient-feeling setting makes it one of the better summer festival venues in northern Greece.