1) Limestone cave 
[cave] Snezhanka (Снежанка, `Snow White`) is a show cave in the Rhodope Mountains, some 5 km away from the town of Peshtera, southern Bulgaria. It was discovered in 1961. To reach it requires a half an hour uphill. Some of the most beautiful cave formations in Bulgaria can be seen inside. The cave is 145 metres long, with a constant...