Bacho Kiro Cave
Bacho Kiro cave is the first utilized cave in Bulgaria. It is situated close to Dryanovo Monastery. The cave has 4 levels, and its galleries and tunnels are about 3600 meters long. Researchers and archaeologists have found that the cave has been inhabited during and after the Stone Age, as numerous artefacts such as blades, knives and other subjects made from bone were discovered there.