Sofia is the capital and largest city of Bulgaria. Sofia is located at the foot of Mount Vitosha in the western part of the country. It occupies a strategic position at the centre of the Balkan Peninsula. Sofia's history spans 2,400 years. Its ancient name Serdica derives from the local Celtic tribe of the Serdi who established the town in the 5th century BC. It remained a relatively small settlement until 1879, when it was declared the capital of Bulgaria. The city’s churches and monuments reflect more than 2,000 years of history, including Greek, Roman, Ottoman and Soviet occupation.

Sofia is the 15th largest city in the European Union with a population of around 1.3 million people, or 1,241,396 in the city proper. It has been ranked by the Globalization and World Cities Research Network as a Beta− city. Many of the major universities, cultural institutions, and businesses of Bulgaria are concentrated in Sofia.