These gardens were first established in the 12th century and over time have expanded to cover more than 400 hectares (988 acres). Surrounded by walls, with gates at each corner, the gardens house large groves of fruit and olive trees along with a series of pools, all of which are fed by a system of underground channels that amazingly come all the way from the Ourika Valley at the base of the Atlas mountains, more than 30km (18 miles) away. The largest of the pools, Sahraj el Hana (Tank of Health), is flanked by an old minzah (pavilion) where the last precolonial sultans would have enjoyed extravagant picnics and parties. The pathways around the pool's edge are paved, shaded, and a delight for a picnic.