The pine-covered headland between the bays—a nice spot for a picnic—supports a Kastro, a stone fortress with intact walls that seem to protect the town even today. Built by the Byzantines on a 600 BC temple of Apollo, it was repaired with available material (note the ancient pillars crammed between the stones) by Francesco Gateluzzi of the famous Genoese family. Look above the gates for the two-headed eagle of the Palaiologos emperors, the horseshoe arms of the Gateluzzi family, and inscriptions made by Turks, who enlarged it; today it is a military bastion. Inside the castle there's only a crumbling prison and a Roman cistern, but you should make the visit for the fine view.
On hill, northeast of port, Mytilini, Lesvos, 81100, Greece