Archaeological site Kathedrale Korykos in Erdemli

You're standing among the remains of Corycus, an ancient port city on the coast of today's Kızkalesi in Turkey. Start with the castle on the mainland right next to you. It has rectangular double walls and square towers. Look closely at the stones. Here and there you'll spot chunks of old columns built into the walls. The builders simply took their material from the ancient city next door.