We begin our tour of the Sultanahmet district, the heart of old Istanbul, at Hagia Sophia*. Built by the Emperor Justinian in the early 6th century AD and designed by Anthemius of Tralles and Isodore of Miletus, the church is one of the marvels of world architecture. Converted into a mosque in 1453, it is now a museum. Its massive dome still dominates the skyline of old Istanbul. It is also famed for its mosaics, including glittering portraits of emperors and empresses and a poignant Virgin and Child
