While Istanbul is famous for its large mosques such as the Hagia Sophia, its smaller mosques are also worth a visit for being equally beautiful, and the Little Hagia Sophia is one such mosque, as it was originally built as an Eastern Orthodox church in the 6th century by Emperor Justinian early in his reign It was converted into a mosque during the Ottoman Empire, and some believe that it was built to be a miniature model of Hagia Sophia, hence the name "Little Hagia Sophia".