It is one of the world’s great buildings. Dating from the sixth century, originally a basilica constructed for the Eastern Roman Emperor Justinian. A masterwork of Roman engineering, the huge 30 m diameter dome covers what was for over 1000 years the largest enclosed space in the world. Unfortunately the church was looted by the fourth Crusaders in 1204, and became a mosque in the 15th century when The Ottomans conquered the city. It was converted into a museum in 1935. History remains palpable here. Byzantine motifs, medallions inscribed with Arabic calligraphy and perennial scaffolding sit together in happy juxtaposition, each quietly attesting to the various incarnations of the building: cathedral, mosque, museum and architectural treasure. And here you encounter a microcosm of modern Turkey, in fact the Turks come, as all visitors do, to appreciate this venerable building, the product of a long, tumultuous history.
Don't miss the excellent mosaics, including those in the gallery, reached by a stone ramp to the left of the entrance. As of September 2008, entrance fee is 20 YTL, about 10 Euro.
NOTE: the inside is undergoing a major refurbishment and there is a huge amount of scaffolding in a gigantic tower going up to the top of the dome. You can also hire a guide at the entrance of the museum.