Sanchova dupka was discovered and explored by members of the Chepelare Cave Club in 1965 but during an International Cave Expedition in 1966 it was again studied by a team consisting of Victor Duglyanski and Igor Efremov, Kurt Brendel and Friedrich Shuster, Dimitar Sabev and Dimitar Raichev. Its height makes it the youngest cave in the sub-region with a presumed young-pleistocene age. In this cave you can find many interesting ponds, full of cave pearls. From the central hall, sized 10/12 meters, two galleries emerge – northern and southern. There are larger halls in both of them with an average size of 20/30 meters.
The floor of the central hall is covered with large gravitational blocks, different in age, tectonics and morphology. The gallery, which is separated from its northwest end, enters the northern part of the cave. This spacious and long gallery connects successively three huge halls, covered tightly with huge gravitational blocks, probably of tectonic origin. The southernmost of the halls has a size of 27/32 m. From its southeast there is a narrow 150-meter gallery, decorated with secondary karst forms. Several levels of water are clearly visible in it. In the southern part of the gallery there is a strong current which shows that the gallery has a connection either with other galleries of the cave or with other caves.