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 these 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 Cyrillic 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 as a result of the Russo-Turkish War, 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, but not yet a member of the Eurozone.
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 Rodopes 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 or Duhlata in the Vitosha Mountain which is 18,200 m long. Orlova Čuka (L=13,437m), and Iagodinska Peštera (L=8,250m) are the longest caves we have listed. The deepest cave of Bulgaria is Kolkina Dupka near Zimevitsa, Sofia Province, with a vertical range of 541 m, and it is also the third longest with 10,300 m. Other deep caves are Raychovata Dupka Cave (-372m), Barki N14 (-350m), and Kipilovo (-350m). The first Bulgarian speleological society was established in 1929. However, the Bulgarian cavers were very successful during recent years in discovering and exploring new caves, so this is subject to change.
The first show caves were Пещерата Лепеница (Lepenitza Cave) in the early 1930s and Bacho Kiro, opened to the public in 1937. In old (socialist) guidebooks six show caves were listed for Bulgaria, we believe that this was the number of official show cave operated by the government during socialist times. Currently, we have 15 show caves listed , a number which changes frequently. New show caves are opened, old show caves are reopened, and some are closed again after a few years due to a lack of visitors or other reasons.
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.