Bulgaria is a very attractive tourist destination because of the numerous natural phenomena, scattered across the country – mountain passes and gorges, rock pyramids and bizarre rock formations, numerous caves and waterfalls, beautiful secluded lakes. Here are some of the best known landscapes: Melnik Pyramids, the Stone Forest near Varna, Belogradchik Rocks, Trigrad Gorge in the Rhodopes, the defiles of the rivers Iskar, Struma, and Mesta, Kardzhali Rock Formations, the Seven Rila Lakes, the canyon of the Rusenski Lom River.  
     Rila and Pirin Mountains impress with their cirques, glacial valleys and carling pinnacles.  
     There is a great diversity of Karst forms, among these some 4,300 caves. The deepest cave in Bulgaria is 415 m deep, and the longest – 15,535 m long. Many of the caves have electric power and have been adapted for visits by tourists. The best known are Ledenika, Magurata, and Saeva Dupka caves in the Balkan Range; Snezhanka (Snow White), Yagodina, Devil's Throat, and Uhlovitsa Cave – in the Rhodopes.
     From December to April the highlands in Rila, Pirin, Vitosha, the Balkan Range and the Rhodopes offer favorable skiing conditions. The best-known mountain resorts are Borovets and Malyovitsa in Rila, Pamporovo in the Rhodopes, Bansko in Pirin, and Aleko in Vitosha - near the capital of Sofia.