The Mosque of al-Mutawakkil

 The first mosque, built in 836, has now disappeared; it was replaced in 849-852 by a new mosque built on a grand scale, which for a long time was the largest mosque of the Islamic world. It continued to be used until the end of the 11th century.

The mosque itself measures 239 x 156m, with 17 aisles in the prayer hall and a triple portico around the courtyard. The piers were reconstructed as octagonal with marble columns on the corners; however, only one pier base exists today. The mihrab was decorated with glass mosaic, of which only small fragments survived. The excavations of the Iraq Directorate of Antiquities in the 1960s discovered in situ fragments of panels of dark blue glass, which lined the walls.

The mosque is set in an outer enclosure measuring 374 x 443m. In this enclosure there are covered porticoes to accommodate additional faithful at the Friday prayer (ziyada), and a building behind the mihrab which seems to have been intended to receive the Caliph, and perhaps accommodate the imam of the mosque.

The famous minaret is 52 m high, with a square base, and a spiral exterior staircase, up which the caliph al-Mutawakkil is said to have ridden on a white Egyptian donkey. At the top there are traces of a wooden pavilion to protect the muezzin.

Three avenues, 52 m wide, were cut through the houses to permit easy access to the mosque.