As one of the finest architectural marvels, as well as one of the largest churches, in the world, Hagia Sophia is Istanbul’s most famous landmark. The building you see today represents many cultures.Known in Turkish as “Ayasofya” (Sacred Wisdom), Hagia Sophia has been of major religious importance to the region, and for various faiths. The church was first commissioned by the Romans and was opened in A.D. 360 before becoming Constantinople’s main Christian place of worship. After riots destroyed the building not once but twice, a new basilica was eventually built in the sixth century, and the Hagia Sophia became the center of Eastern Orthodox Christianity.When the Ottoman Empire took control of Constantinople in 1453, Hagia Sophia was turned into a mosque. Its Christian features were covered or removed, and new Islamic features were added. Shortly after the Turkish Republic was proclaimed, Constantinople became Istanbul and the mosque was closed. The national monument is now open to the public as a museum.With its four spectacular minarets and its grand central dome, the Hagia Sophia dominates the Istanbul skyline. Enter the church via the western portal. From the exonarthex, five portals open into the narthex. Admire ninth-century mosaics and 10th-century frescos from the Christian faiths. Note that the dome is decorated with Islamic inscription of verses from the Quran. The eastern corner of the gardens house the mausoleums of several sultans.Since the Hagia Sophia is Istanbul’s leading cultural treasure, there are often long lines outside. However, visitors rarely have to wait more than half an hour to get in. Refreshments can be bought from a number of different cafés in the square.Hagia Sophia is located in the Old City, and is accessible by public transport. The building is open daily, except Mondays. Visiting hours are longer in summer. Buy your entry ticket at the museum’s box office. Consider renting an audio guide to get a better understanding of the educational and cultural value of the Hagia Sophia.