Zeyrek Mosque - Credit: Wikimedia Commons
Zeyrek Mosque () or the Monastery of the Pantokrator (, in ), is a large mosque in Fazilet Sokağı in the Zeyrek district of Fatih in Istanbul, overlooking the Golden Horn. It is made up of two former Byzantine churches and a chapel joined together and represents the best example of Middle Byzantine architecture in Constantinople. After Hagia Sophia, it is the largest Byzantine religious edifice still standing in Istanbul. Read more on Wikipedia
Source: en.wikipedia.org