Hagia (St.) Sophia
Hagia Sophia is an architectural monument of great in both Byzantine and Ottoman terms. Built as a church, then transformed into a mosque in 1453, it is now a museum. The first Haghia Sophia was partially burnt during an uprising. It was restored by Theodosius II and opened for worship in 415, but it was burned down during a public uprising in 532.
The structure was known in Byzantium as the basilica Cistern, Justinian was the founder of the largest underground cistern, built after the Nika Revolt in 532.The number of the inhabitants of Constantinople increased and bring a problem of water supply.
The Hippodrome of Constantinople (Turkish: SultanahmetMeydani, At Meydani) was a circus that was the sporting and social centre of Constantinople, capital of the Byzantine Empire. Today it is a square named SultanahmetMeydani (Sultan Ahmet Square) in the Turkish city of Istanbul, with only a few fragments of the original structure surviving.