Geographically and climatically, Bulgaria is noted for its diversity, with the landscape ranging from the Alpine snow-capped peaks in Rila, Pirin and the Balkan Mountains to the mild and sunny weather of the Black Sea coast, from the typically continental Danubian Plain (ancient Moesia) in the north to the strong Mediterranean influence in the valleys of Macedonia and the lowlands in the southernmost parts of Thrace. Bulgaria comprises portions of the classical regions of Thrace, Moesia, and Macedonia. The southwest of the country is mountainous with two alpine ranges - Rila and Pirin, and further east are the lower but more extensive Rhodope Mountains. Rila mountain includes the highest peak of the Balkan Peninsula, peak Musala at 2,925 meters (9,596 ft); the long range of the Balkan mountains runs west-east through the middle of the country, north of the famous Rose Valley. Hilly country and plains are found in the southeast, along the Black Sea coast in the east, and along Bulgaria's main river, the Danube in the north. Other major rivers include the Struma and the Maritsa river in the south. There are around 260 glacial lakes situated in Rila and Pirin, several large lakes on the Black Sea coast and more than 2,200 dam lakes. Mineral springs are in great abundance located mainly in the south-western and central parts of the country along the faults between the mountains.


The Bulgarian climate is temperate, with cool, damp winters, very hot, dry summers, and Mediterranean influence along the Black Sea coast. The barrier effect of the Balkan Mountains is felt throughout the country: Northern Bulgaria is slightly cooler and receives more rain than the southern regions. Average precipitation in Bulgaria is about 630 millimetres per year. The driest areas are Dobrudzha and the northern coastal strip, while the higher parts of the mountains Rila and Stara Planina receive the highest levels of precipitation. In summer, temperatures in the south of Bulgaria often exceed 40 degrees Celsius, but remain cooler by the coast.

The country is relatively rich in mineral resources, including vast reserves of lignite and anthracite coal; non-ferrous ores such as copper, lead, zinc and gold. There are large deposits of manganese ore to north-east. There are smaller deposits of iron, silver, chromite, nickel and others. Bulgaria is rich in non-metalliferous minerals such as rock-salt, gypsum, kaolin, marble.

The Balkan peninsula derives its name from the Balkan or Stara Planina mountain range which runs through the centre of Bulgaria into eastern Serbia.The largest cities in the country are Sofia (1,246,791), Plovdiv (376,918), Varna (345,522), Burgas (259,985), Rousse (176,118) Stara Zagora (163,193), Pleven (121,700), Dobrich (115,861), Sliven (106,434);Bulgaria has a scientific base on Livingston Island in the South Shetland Islands, Antarctica.