The capital of the country and the largest city in Bulgaria is Sofia, a city located in the western part of the country, at the foot of the Vitosha massif.

The city lies on the Bojana River, which is a left tributary of the Iskar River (the right tributary of the Danube). Sofia is a separate urban region and is also the administrative center of the Sofia Oblast. In 2016, the city had a population of over 1 million 290 thousand people.