Religion is very strict when it comes to the places of cult where you practice it and these places differ very much depending on that particular religion. You can recognize a Roman-Catholic church from the outside and also a synagogue or a mosque. That is possible because they have a totally different architecture. But sometimes all these rules are broken and you face a wonderful mixture and styles and that’s what makes the place unique. I am talking now about Hagia Sofia or Ayasofya in Istanbul that is presently a museum and one of the most famous remnants of Byzantine architecture.
It was in turns an Eastern Orthodox Cathedral, a Roman Catholic Cathedral and a Mosque, all in different times in history, depending on who conquered Istanbul or Constantinople at the time. So it looks like an Orthodox Church with Muslim minarets. It is unusual, yet incredibly beautiful and each cult has left nice marks on it. The original cathedral was built by Isidore of Miletus Anthemius of Tralles and is decorated on the inside with mosaique and marble pillars. It is tall and richly decorated, preserving in a perfect manner the base-reliefs that were specific to Byzantine architecture. It was a place for coronations and asylum for the ones in need and still attracts lots of tourists or pilgrims every year, because it really is a wonderful architectural monument.