Guadalest Reservoir from Benimantell Nature · Benimantell, La Marina Baixa, Alicante The Guadalest reservoir, visible from the town centre of Benimantell at 547 metres above sea level, on the foothills of the Sierra de Aitana, collects the waters of the río Guadalest, a tributary of the Algar. It is a concrete gravity dam 94 metres high and 236 metres long at the crest, with a capacity of 13 cubic hectometres and a water surface of 86 hectares. Photo: Diego Delso (CC BY-SA 4.0) What to see and do in Benimantell