text:  It is principally from Ibn Hayyan that Al-Makkari has copied the details of this marvellous structure with its "15 000 doors counting each flap or fold as one " all covered either with plates of iron or sheets of polished brass; and its 4000 columns great and small 140 of which were presented by the Emperor of Constantinople and 1013 mostly of green and rose-coloured marble were brought from various parts of Africa