The Almohades were untiring builders: the Kasbah', the Agdals the water tanks; but their masterpiece was incontestably the three large mosques of the Empire: Koutoubia, Giralda, Turn-Hassan. The Mosque of the booksellers was thus called because one could sell books and manuscripts in a neighbouring street. It was built on the site of the palace of the Almoravides between 1158 and 1199 and is known as one of the largest mosques of the Moslem Occident with 16 parallel naves and a broader central nave. Its interior decoration is particularly rich. From any side where one can see its minaret, one remains seized by its beauty, its pure lines are established harmoniously in the Médina and contrast on the massive shape of the High Atlas located at 60 km towards the south.

This 71 m high tower is monumental, however it keeps a great simplicity thanks to the relation (width-height) from 1 to 5 adopted. Its rubble stones of sandstone from the guéliz are covered by a plaster and lime coating. Sometimes painted in its higher part, very light decoration varies on each side “nowhere better than in Koutoubia does the width and the volunteer sobriety of the art of Almohades appear”. There is no staircase but a slope and 6 stages of superposed rooms.