Rotonda Sveti Georgi (Rotunda of St George)
Standing in the courtyard of the Sheraton Balkan Hotel, the tiny sunken redbrick Rotunda of St George is the oldest preserved building in Sofia, built in the fourth century as a Roman temple. Careful restoration work has revealed three layers of exquisite medieval frescoes, which had been hidden by plaster during the 500 years of Ottoman rule. The impressive cupola bears a 14th-century portrait of Christ the Pantocrator, surrounded by four angels and symbols of the Evangelists. Beneath, 12th-century fresco work depicts 22 prophets holding scrolls, with texts alternately in Bulgarian and Greek. To the east lie excavated foundations of an octagonal-shaped Roman public building and paved street.