This is the interior of the Haga Sofia. It is now a museum in Istanbul. But it was once (and for 500 + years) the largest building in volume in the world. It was built as the Byzantine center of Orthodox (Eastern Catholic) religion, back when Istanbul was Byzantium and later Constantinople.
Once taken by the Ottaman Empire, it was converted to a mosque, which is when the calligraphy was added. In the center of the picture, the steps up to the pulpit (not called a pulpit in Islam, but you know what I mean) is all made from 1 piece of carved marble.
After World War 1, when Attaturk became the President and modernizer of Turkey, he converted Haga Sofia into a Museum. It is stunning.