On a mountain
Krivus Fortress
Krivus is a medieval Bulgarian fortress, built in the 10th century.
Momchil’s Fortress
Momchil’s Fortress lies near Gradat Village, Smolyan Municipality.
Monyak Fortress
The Monyak Fortress (also known as Mneakos, Mniyak) is in the Rhodope Mountain, 11 km east of the city Kardzhali near the village of Shiroko Pole, and is 586 meters above sea level.
Ustra Fortress
The Ustra fortress, situated near the village of Ustra, is one of the highest strongholds in the Rhodope mountain.
Tsepina Fortress
The Tsepina Fortress is situated a few kilometers north-west of the Rhodope village of Dorkovo.
Ledenika Cave
Ledenika Cave is situated at a distance of 16 km from the town of Vratsa, in the territory of Vratsa Balkan Natural Park.