Sofia is the capital and largest city of Bulgaria. The city has a population of 1.26 million, while over 1.5 million people live in its functional urban area. The city is located at the foot of Vitosha Mountain in the western part of the country, within less than 50 kilometres (31 mi) drive from the Serbian border. Its location in the centre of the Balkan peninsula means that it is the midway between the Black Sea and the Adriatic Sea, whereas the Aegean Sea is the closest to it.
Sofia has been an area of human habitation since at least 7000 BCE. Being Bulgaria's primate city, Sofia is a hometown of many of the major local universities, cultural institutions and commercial companies. Sofia is one of the top 10 best places for start-up businesses in the world, especially in IT technologies. Sofia is Europe's most affordable capital to visit as of 2013.
Sofia has an area of 492 km2, while Sofia City Province has an area of 1344 km2. Sofia's development as a significant settlement owes much to its central position in the Balkans. It is situated in western Bulgaria, at the northern foot of the Vitosha mountain, in the Sofia Valley that is surrounded by the Balkan mountains to the north. The valley has an average altitude of 550 metres.
The city has an extensive green belt. Some of the neighbourhoods constructed after 2000 are densely built-up and often lack green spaces. There are four principal parks – Borisova gradina in the city centre and the Southern, Western and Northern parks. Several smaller parks, among which are the Zaimov Park, City Garden and the Doctors' Garden, are located in central Sofia. The Vitosha Nature Park (the oldest national park in the Balkans) includes most of Vitosha mountain and covers an area of 266 square kilometres (103 sq mi),
Sofia concentrates the majority of Bulgaria's leading performing art troupes. Theatre is by far the most popular form of performing art, and theatrical venues are among the most visited, second only to cinemas. The oldest such institution is the Ivan Vazov National Theatre, which performs mainly classical plays and is situated in the very centre of the city.
Sofia is one of the most visited tourist destinations in Bulgaria alongside coastal and mountain resorts. Among its highlights is the Alexander Nevsky Cathedral, one of the symbols of Bulgaria, constructed in the late 19th century. It occupies an area of 3,170 square metres (34,122 square feet) and can hold 10,000 people.
A large number of sports clubs are based in the city. During the Communist era most sports clubs concentrated on all-round sporting development, therefore CSKA, Levski, Lokomotiv and Slavia are dominant not only in football, but in many other team sports as well. Basketball and volleyball also have strong traditions in Sofia. A notable local basketball team is twice European Champions Cup finalist Lukoil Akademik.
The city is home to a number of large sports venues, including the 43,000-seat Vasil Levski National Stadium which hosts international football matches, as well as the Georgi Asparuhov Stadium and Lokomotiv Stadium, the main venues for outdoor musical concerts. Armeets Arena holds many indoor events and has a capacity of up to 19,000 people depending on its use.