Built by the Romans during the first through third centuries, the Belogradchik Fortress sits a short distance from the northwestern Bulgarian town of -- you guessed it -- Belogradchik.
The fortress has survived some of the world's greatest empires, from the Roman to the Byzantine. Much of what remains today was built in the 19th century.
Belogradchik Fortress is the town's biggest tourist attraction and visitors today can explore the grounds, bunkers and even the rocks that peer over the site.
Check out images of Belogradchik Fortress below!