Cortes-La Muela Reservoir (sometimes referred to as Cortes II Reservoir) is an arch dam and hydroelectric project built on the mid-course of the Júcar River, located in the town of Cortes de Pallás, within the province of Valencia, in the Valencian Community, Spain.

The Cortes Reservoir and dam, together with La Muela I hydroelectric power station, were built between 1983 and 1988. The pumped-storage hydroelectric power station has an installed capacity of 630 megawatts (840,000 hp) for generation and 540 megawatts (720,000 hp) for pumping.

Later, between 2006 and 2013, La Muela II pumped-storage power station was constructed, with an installed capacity of 850 megawatts (1,140,000 hp) for generation and 740 megawatts (990,000 hp) for pumping. This established the complex as a major hydroelectric facility within the Iberian Peninsula, with 1,520 megawatts (2,040,000 hp) in pumping capacity. The reservoir covers an area of 115 hectares (280 acres) and has a capacity of 116 cubic hectometres (94,000 acre⋅ft).

As of 2018, it was the largest pumped hydroelectric storage plant in Europe. The project comprises a dam and large reservoir, a conventional hydroelectric power station and two underground pumped-storage hydroelectric power stations that, together, generate approximately 5,000 GWh (18,000 TJ) per annum.

According to en.wikipedia.org