Citadel of Damascus
In September 1183, construction of the Cairo Citadel began under Saladin's orders. According to al-Maqrizi, Saladin chose the Muqattam Hills to build the citadel because the air there was fresher than anywhere else in the city, but its construction was not so much determined by the salubrious atmosphere; rather it was out of defensive necessity and example of existing fortresses and citadels in Syria. The walls and towers of the northern section of the citadel are largely the works of Saladin and al-Kamil. Al-Kamil completed the citadel; he strengthened and enlarged some of the existing towers (such as two of Saladin's towers that were enlarged by totally encasing them in semi-circular units), and also added a number of square towers which served as self-contained keeps. According to Richard Yeomans, the most impressive of al-Kamil's structures was the series of massive rectangular keeps which straddled the walls of the northern enclosure. All of al-Kamil's fortifications can be identified by their embossed, rusticated masonry, whereas Saladin's towers have smooth dressed stones. This heavier rustic style became a common feature in other Ayyubid fortifications, and can be seen in the Citadel of Damascus and that of Bosra in Syria.