Great Mosque of Raqqa - Credit: Wikimedia Commons
The Great Mosque of Raqqa () or Al-Qadim Mosque () is the oldest mosque in Raqqa, Syria, located at the northern section of the city's heart. It has a rectangular plan ( x ) with thick mud brick walls fortified with semi-circular towers at the corners.Great Mosque of Raqqa Archnet Digital Library. The outer walls of the mosque are constructed of mud bricks supported by solid semi-circular buttress towers. The prayer hall consisted of three arcades supported on cylindrical piers, whilst the other three sides were lined with double arcades. The building is decorated with stucco, traces of which survive.Petersen, 1999, p.245. Read more on Wikipedia
Source: en.wikipedia.org