The Orthodox Church “St. George” is located in the courtyard between the buildings of the Balkan Hotel \Sheraton\ and the Presidency at a level a few meters below the modern streets of Sofia. It is believed to be the oldest preserved building in the city, built at a time when Sofia was the residence of the emperors Galerius and Constantine the Great. The church is part of a large complex of ancient buildings from the end of the 3rd century and the beginning of 4th. Its dome rises to 13.70 m from the floor, but despite the small size this monument has an impressive impact and it is also subject to extensive research and interest. The building was used during its long existence as a public, religious, residential place, and was transformed into a mosque from the 6th to the 19th century. The interior hosts fragments of five layers of frescoes of different ages. Besides religious activities held In the Rotunda there are also military ceremonies and concerts with Orthodox and classical music.