1) Castle in Bulgaria 
[fortress] Ktenia (Ктения, Κτένια) is a ruined Roman and medieval fortress, situated 2.1 km to the north of the village of Lozarevo in Sungurlare Municipality, Burgas Province, south-eastern Bulgaria. In the Middle Ages, Ktenia often changed hands between Bulgaria and Byzantium. The ruins of the fortress lie northeast of the tow...