Bulgaria (България), officially the Republic of Bulgaria (Bulgarian: Република България), is a country in Southeastern Europe. It is bordered by 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 capital and largest city is Sofia; other major cities are Plovdiv, Varna, and Burgas. With a territory of 110,994 square kilometers (42,855 sq mi), Bulgaria is Europe’s sixteenth-largest country.
Bulgaria occupies a portion of the eastern Balkan peninsula, bordering five countries—Greece and Turkey to the south, Macedonia and Serbia to the west, and Romania to the north. The land borders have a total length of 1,808 kilometers (1,123 mi), and the coastline has a length of 354 kilometers (220 mi). Its total area of 110,994 square kilometers (42,855 sq mi) ranks it as the world’s 105th-largest country. Bulgaria’s geographic coordinates are 43° N 25° E.
The most notable topographical features are the Danubian Plain, the Balkan Mountains, the Thracian Plain, and the Rila-Rhodope massif. The southern edge of the Danubian Plain slopes upward into the foothills of the Balkans, while the Danube defines the border with Romania. The Thracian Plain is roughly triangular, beginning southeast of Sofia and broadening as it reaches the Black Sea coast.
The Balkan mountains run laterally through the middle of the country from west to east. The mountainous southwest has two distinct alpine type ranges – Rila and Pirin, which border the lower but more extensive Rhodope Mountains to the east, and various medium-altitude mountains to west, northwest and south, like Vitosha, Osogovo and Belasitsa. Musala, at 2,925 meters (9,596 ft), is the highest point in both Bulgaria and the Balkan peninsula.
The Black Sea coast is the country’s lowest point. Plains occupy about one-third of the territory, while plateaux and hills occupy 41%. Most rivers are short and with low water levels. The longest river located solely in Bulgarian territory, the Iskar, has a length of 368 kilometers (229 mi). The Struma and the Maritsa are two major rivers in the south.
Bulgaria has a varied and changeable climate, which results from being positioned at the meeting point of the Mediterranean, Oceanic and Continental air masses combined with the barrier effect of its mountains. Northern Bulgaria averages 1 °C (1.8 °F) cooler and registers 200 millimeters (7.9 in) more precipitation, than the regions south of the Balkan mountains.
Temperature amplitudes vary significantly in different areas. The lowest recorded temperature is −38.3 °C (−36.9 °F), while the highest is 45.2 °C (113.4 °F). Precipitation averages about 630 millimeters (24.8 in) per year, and varies from 500 millimeters (19.7 in) in Dobrudja to more than 2,500 millimeters (98.4 in) in the mountains. Continental air masses bring significant amounts of snowfall during winter.
The interaction of climatic, hydrological, geological and topographical conditions has produced a relatively wide variety of plant and animal species. Bulgaria’s biodiversity, one of the richest in Europe, is conserved in three national parks, 11 nature parks, 10 biosphere reserves and 565 protected areas. Ninety-three of the 233 mammal species of Europe are found in Bulgaria, along with 49% of butterfly and 30% of vascular plant species. Overall, 41,493 plant and animal species are present.
Larger mammals with sizable populations include deer (106,323 individuals), wild boars (88,948), jackals (47,293) and foxes (32,326). Partridges number some 328,000 individuals, making them the most widespread game bird. A third of all nesting birds in Bulgaria can be found in Rila National Park, which also hosts Arctic and alpine species at high altitudes. Flora includes more than 3,800 vascular plant species of which 170 are endemic and 150 are considered endangered. A checklist of larger fungi in Bulgaria by the Institute of Botany identifies more than 1,500 species. More than 35% of the land area is covered by forests.
In 1998, the Bulgarian government adopted the National Biological Diversity Conservation Strategy, a comprehensive programme seeking the preservation of local ecosystems, protection of endangered species and conservation of genetic resources. Bulgaria has some of the largest Natura 2000 areas in Europe covering 33.8% of its territory. It also achieved its Kyoto Protocol objective of reducing carbon dioxide emissions by 30% from 1990 to 2009.
Bulgaria ranks 30th in the 2018 Environmental Performance Index, but scores low on air quality. Particulate levels are the highest in Europe, especially in urban areas affected by automobile traffic and coal-based power stations. One of these, the lignite-fired Maritsa Iztok-2 station, is causing the highest damage to health and the environment in the European Union.
Pesticide use in agriculture and antiquated industrial sewage systems produce extensive soil and water pollution. Water quality began to improve in 1998 and has maintained a trend of moderate improvement. Over 75% of surface rivers meet European standards for good quality.