Constructed during the ninth century by the Aghlabid dynasty, the Aghlabid Pools are to provide adequate drinking water for the inhabitants of the arid city of Kairouan. It is a hydraulic set consisting of a pond and two reinforced water tanks fed by a channel up to 36 miles long. The pond filters the water as the sediment collects before transporting Water to the larger basin, but today it has been converted into a garden with facilities for visitors.