Hagia Sophia (Ayasofya), completed in 537 AD under Byzantine Emperor Justinian I, is one of the world's greatest architectural masterpieces, standing in the heart of Istanbul, a city of 15 million. For nearly 1,000 years the world's largest cathedral, then an Ottoman mosque, then a museum, and since 2020 a mosque once more — its soaring dome and golden mosaics are breathtaking. An unmissable icon for travel art lovers. Coordinates: 41.0086° N, 28.9802° E















