 The gardens are irrigated using a number of pools and ditches.A network of underground channels and ditches, known as "khettera", bring water down from the High Atlas mountains many kilometres away, via Aghmat in the Ourika Valley to the south.The "Dar El Hana", a small pavilion or "minzah", stands beside the largest pool, the "Sahraj el-Hana" (Tank of Health), which was used to train troops to swim.