Mosque of Ibn Tulun at Cairo, Egypt.
Porticoes with slightly pointed arcades surround the prayer room (maqsura) to form a walled courtyard. This courtyard (sahn) originally contained a fountain for the faithful to wash their feet in before entering the maqsura. The tower (minaret) on the left is where the call to prayer services is issued. It is highly debated as to whether or not the minaret was part of the original structure, or added at a later date.
The interior continues with the prominent motif of pointed arches. The sacred nich (mihrab) that points to mecca is a pointed arch set in a square frame, and richly decorated with glazed ceramic tiles and marble. Calligraphy of the Kufic style decorates the inside of the mihrab.