Sancta Sophia is a former Orthodox patriarchal basilica (church), later a mosque, and now a museum in Istanbul, Turkey. From the date of its construction in 537 until 1453, it served as an Eastern Orthodox cathedral and seat of the Patriarchate of Constantinople, except between 1204 and 1261, when it was converted to a Roman Catholic cathedral under the Latin Empire. The building was a mosque from 29 May 1453 until 1931. It was then secularized and opened as a museum on 1 February 1935.
Among the many landmarks in Turkey, the three famous mosques of Istanbul that deserve special attention. The most beautiful one - The Blue Mosque - is considered the greatest masterpiece not only of Islamic architecture, but also of the world.
The Blue Mosque was built after a series of Turkish military defeats. Sultan Ahmed I realized that no new mosque had been built in the city for about forty years, so he decided to please Allah and remedy the situation. The construction began in August of 1609 when the sultan was 19 years old. (http://www.airpano.com/360Degree-VirtualTour.php?3D=Mosques-Istanbul-Turkey)
I wanted to get the right information about this stunning place I got to visit. It was unreal, I'm so glad I got to see it.