Lake Yacoub el Mansour is the reservoir created by the Ouirgane dam on the Oued Nfis river, sitting right on the edge of the village at around 1,000 metres elevation. The lake is a beautiful thing — green-blue water framed by bare terracotta mountains and the occasional walnut tree — and the dam wall provides a fine vantage point over the valley.
Walking along the lake shore is one of the easiest and most rewarding activities in Ouirgane. Several trails follow the water before climbing into the surrounding hills, passing through Berber farmsteads and small orchards. The lake also attracts kingfishers, herons, and other waterbirds that make it worth a slow, quiet circuit with binoculars. Early morning, before the day trippers from Marrakech arrive, the whole scene is particularly peaceful.