There are more than 40 mountains in Bulgaria. Stara Planina stretches from the Belogradchik Passage to Emine Cape on the Black Sea. It is 530 km long and 15-50 km wide. It is connected with Sredna Gora through a number of mountain thresholds among which are The Sub-Balkan Mountain Valleys (Karlovo Mountain Valley, Kazanluk Mountain Valley, etc.). Vitosha and Sakar Mountains, the Upper Thracian Lowland and the Bourgas Lowland are situated between Sredna Gora and the Rila-Rhodope Massif. The latter consists of Rila (peak Moussala – 2,925 m – is highest on the Balkan Peninsula), Pirin and Rhodope Mountains. Rila and Pirin have beautiful cirque lakes, cirques, glacial valleys and moraines, and the Rhodopes have caves, gorges and rock phenomena. To the southwest there are the so-called Ogradni Planini /Fencing Mountains/ and the valley of the Strouma River, and to the southeast there is the Strandzha Mountain.