Bulgaria is located in southeastern Europe. It has a coast to the Black Sea at the eastern side (354 km coastline), to the north it borders Romania (608km) and to the south Turkey (240km) and Greece (494km). The western border is to former Yugoslavia, today this are Serbia and Montenegro (318km) and the Republic of Macedonia (148km).
Bulgaria has a population of 7.5 Million people, the Capital is Sofia with a population of 1.1 Million people. The main Religion is Bulgarian Orthodox (80%), followed by Muslim (18%). The spoken language is Bulgarian, it is written in the Kyrillic alphabet.
During the Roman Empire the area of Bulgaria was inhabited by the Thrakians. The Bulgars, who gave the country its name, were a Central Asian Turkic tribe. They merged with the local Slavic inhabitants in the late 7th century to form the first Bulgarian state. In the 14th century the country was overrun by the Ottoman Turks. Bulgaria regained its independence in 1878, the Liberation Day is still a National holiday. In both World Wars Bulgaria fought on the losing side. Between 1946 and 1990 Bulgaria was a People's Republic and part of the Warsaw Pact. Today it is a democracy named Republic of Bulgaria and on its way to a market economy, but it is still very poor and has the problems of high inflation and unemployment. Bulgaria is a member of the European Union, NATO, and the Council of Europe.
Bulgaria is very mountainous. There are only two lowlands to the north and the southeast. The mountain ridges follow the borders, so Bulgaria is surrounded by mountains. Most caves of Bulgaria are located in the limestone areas of the mountains north of Sofia towards the Romanian border. More karst caves can be found in the marble of the Rhodopes along the Greek border.
At the moment 4,500 caves are known (cave registry 2002). Most of them are karst caves, but there are also 60 volcanic caves and three sandstone caves. The longest cave is Douhlata in the Vitosha Mountain which is 18,200 m long. The deepest cave of Bulgaria is Kolkina Dupka near Zimevitsa, Sofia Province, with a vertical range of 541 m. The first Bulgarian speleological society was established in 1929. The first show cave is Bacho Kiro, opened to the public in 1937.
Bulgaria has a wealth of cultural heritage. There are numerous places which are inscribed on the UNESCO World Heritage List. The most important museums are located at Sofia.