Overhead drone shot of the natural rock formations of Belogradchik Fortress which used to be an ancient Roman stronghold on the slopes of the Balkan Mountains in Vidin province, Bulgaria

belogradchik vidin province bulgaria northwestern balkan mountains danube river belogradchik rocks tourism medieval fortress magura cave baba vida kaleto the fortress roman empire fortified walls ottoman conquest castle architecture europe rocks tourists scenic picturesque view tourist spots travel aerial drone shots panoramic historical culture world heritage unesco rock formations natural nature educational geologic structures morphological ecotourism attractions destinations adventures boulders crags grass clouds misty fog