Bulgaria is a country situated in Southeast Europe that occupies the eastern quarter of the Balkan peninsula, being the largest country within its geographic boundaries. It borders Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east. The northern border with Romania follows the river Danube until the city of Silistra. The land area of Bulgaria is 110,994 square kilometres (42,855 sq mi), slightly larger than that of Cuba, Iceland or the U.S. state of Tennessee. Considering its relatively compact territorial size and shape, Bulgaria has a great variety of topographical features. Even within small parts of the country, the land may be divided into plains, plateaus, hills, mountains, basins, gorges, and deep river valleys. The geographic center of Bulgaria is located in Uzana.
Rila is the highest mountain range of Bulgaria, the Balkan Peninsula and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Massif. The highest summit is Musala at an elevation of 2,925 m which makes Rila the sixth highest mountain range in Europe after the Caucasus, the Alps, Sierra Nevada, the Pyrenees and Mount Etna, and the highest one between the Alps and the Caucasus. It spans a territory of 2,629 km2 with an average elevation of 1487 m. The mountain is believed to have been named after the river of the same name, which comes from the Old Bulgarian verb "рыти" meaning "to grub".
The Pirin Mountains are a mountain range in southwestern Bulgaria, with the highest peak, Vihren, at an altitude of 2,914 m (9,560 ft).
The Vit also Vid is a river in central northern Bulgaria with a length of 188 km. It is a tributary of the Danube. The source of the Vit is in Stara Planina, below Vezhen Peak at an altitude of 2,030 meters. It empties into the Danube close to Somovit. The river has a watershed area of 3,228 km2, its main tributaries being Kamenska reka, Kalnik and Tuchenitsa.
The Iskar is a right tributary of the Danube. With a length of 368 km, it is the longest river that runs entirely within Bulgaria. Originating as three forks in Balkan's highest mountain range Rila, the Iskar flows in a northern direction until its confluence with the Danube. As it flows northwards it fuels the largest artificial lake in the country, the Iskar Reservoir, forms the divide between the Vitosha and Plana Mountains in the west and the Sredna Gora mountain range in the east before entering the Sofia Valley, which contains the nation's capital Sofia. From there the Iskar runs through the Balkan Mountains, forming the spectacular 84 km long Iskar Gorge. As it crosses the mountains, its water course turns in a north-eastern direction at Lakatnik. North of the Balkan Mountains, the river crosses the Danubian Plain and finally flows into the Danube between the villages of Baykal and Gigen. Geologically, Iskar is the oldest river in the Balkan Peninsula.
The Topolnitsa is a river in southern Bulgaria, an important left tributary of the Maritsa. The river's name is derived from the Bulgarian word топола, topola ("poplar"). Reaching length of 155 km, the Topolnitsa is the fourth longest river in the Maritsa drainage, following the Tundzha (390 km), the Arda (290 km) and the Ergene (281 km).
Sredna Gora is a mountain range in central Bulgaria, situated south of and parallel to the Balkan Mountains and extending from the river Iskar to the west and the elbow of river Tundzha north of the city of Yambol to the east. Sredna Gora is 285 km long, reaching 50 km at its greatest width. Its highest peak is Golyam Bogdan at 1,604 m (5,262 ft). It is part of the Srednogorie mountain chain system, which extends longitudinally across the most country from west to east, between the Balkan Mountains and the Sub-Balkan valleys to the north and the Kraishte, Rila and the Upper Thracian Plain to the south.
The Stryama is a river in southern Bulgaria, an important left tributary of the Maritsa. It originates in the Balkan Mountains. The river is 110 kilometres in length and is the sixth longest in the Maritsa drainage, following the Tundzha (390 km), the Arda (290 km), the Ergene (281 km), the Topolnitsa (155 km) and the Sazliyka (145 km).
The Rusenski Lom is a river in northeastern Bulgaria, the last major right tributary of the Danube. It is formed by the rivers Beli Lom and Cherni Lom, the former taking its source south of Razgrad and the latter southeast of Popovo.
The Vacha is a river in southern Bulgaria, a right tributary of the river Maritsa. The 112 km long Vacha is the 23rd longest river of Bulgaria and the second longest in the Rhodope Mountains, following the Arda (272 km), another major Maritsa tributary. The Vacha drains significant area of the western Rhodope Mountains, including the ridges Batak Mountain, Veliyshko–Videnishki, Pereliksko–Prespanski and Chernatitsa.
The Danubian Plain constitutes the northern part of Bulgaria, situated north of the Balkan Mountains and south of the Danube. Its western border is the Timok River, and to the east it borders the Black Sea. The plain has an area of 31,523 square kilometres (12,171 sq mi). It is about 500 kilometres (310 mi) long and 20 to 120 kilometres wide.
Golyam Rezen is a peak on Vitosha Mountain in Bulgaria. Rising to 2,277 m, the peak is second to the mountain's summit Cherni Vrah situated 900 m to the west. Golyam Rezen hosts an Air Traffic Services facility, as well as military communications installations. The precipitous east slopes of the peak are a popular rock climbing site, overlooking Bistritsa River Valley in Bistrishko Branishte Biosphere Reserve.
Skoparnik is the third highest peak of Vitosha Mountain in Bulgaria. Rising to 2,226 m, the peak is situated 1.5 km south of Golyam Rezen Peak (2,277 m), and 2 km southeast of the summit Cherni Vrah (2,290 m). The peak is bounded by the Bistrishko Branishte Biosphere Reserve to the east, and a prohibited drinking water catchment area to the west, and is part of the divide between the Black Sea and the Mediterranean, with the Vitoshka Bistritsa draining its eastern slopes to flow into the Iskar River and eventually to the Danube River, and the Struma River draining the western slopes to flow into the Aegean Sea.
Republican Road II-11 is a second-class road in northern Bulgaria spanning half of the Danube border with Romania in the Danubian Plain, running in general direction west–east through the territory of Vidin, Montana, Vratsa and Pleven Provinces. Its length is 213.3 km.
The Chepinska reka , or Chepino river, is a 83 km-long river in southern Bulgaria, a right tributary of the river Maritsa.
The Batak Hydroelectric Cascade is situated in the Pazardzhik Province, southern Bulgaria and is among the first hydroelectric cascades in the country. Inaugurated on 6 September 1959, it includes seven reservoirs and three underground hydro power plants — Batak, Peshtera and Aleko with a combined installed capacity of 254.2 MW, producing an average of 796 GWh annually.
The Belmeken–Sestrimo–Chaira Hydroelectric Cascade is situated in the Pazardzhik Province, southern Bulgaria and is the largest and most complex hydroelectric complex in the country. Located in the eastern part of the Rila mountain range, the complex receives waters from the drainage basins of the major rivers Maritsa, Struma and Mesta. Its catchment area is 458 km2.
The Lesnovska reka is a river in western Bulgaria, a right tributary of the river Iskar, itself a right tributary of the Danube, belonging to the Black Sea drainage. Its length is 65 km. It drains parts of the Ihtimanska Sredna Gora mountain range and the Sofia Valley.
Saranska Valley is situated in central western Bulgaria and is the third of the eleven Sub-Balkan valleys in direction west–east. It is named after the village of Sarantsi.
