The St. George Rotunda
The St. George Rotunda is the oldest preserved building in Sofia.

The St. George Rotunda is the oldest preserved building in Sofia. It dates back to the 4th century. There is a dispute as to whether originally it had been Roman Baths, a sanctuary or a building with functions other than these.
Since 6th century the centraldomed premises with a picturesque ancient "Al Fresco" layer and medieval mural paintings had been used as Christian church (rotunda).