The Church of St. George is believed to be the oldest cultural building in Sofia with its well preserved early Christian architecture. It is located behind the Sheraton hotel, in the center of the ancient ruins of the old Serdika Fortress.
Erected by the Romans in the 4th century, the church has a circular dome built on a square base. It is believed that it was built on the site of a pagan temple. The building is famous for its frescoes in the central dome, dating from the 12th to the 14th centuries. The magnificent frescoes depicting 22 different prophets rise up to 2 meters high. There are also five successive layers of murals, created from the 6th to 14th centuries. The church was painted during the Ottoman rule; at the time the building was a mosque. The frescoes were discovered and restored only in the 20th century.