Cernadilla Reservoir, Reservoir in Cernadilla, Zamora province, Spain

Cernadilla Reservoir is formed by a concrete gravity dam 67 m high and 388 m long on the Tera River, which here marks the boundary between Cernadilla and Manzanal de Arriba. Its crest stands at 892 m above sea level, and the reservoir covers about 13.94 km² with a capacity of 255 million m³. The powerhouse with a Kaplan turbine sits at the foot of the dam on the left bank.

The dam was completed in 1969, damming the Tera River on the boundary between Cernadilla and Manzanal de Arriba. It is owned and operated by Iberdrola Generación S.A. for hydroelectric power and irrigation. The reservoir can begin near Puebla de Sanabria depending on the Tera's flow.

The dam stands in the municipality of Cernadilla, where the Tera forms the boundary with Manzanal de Arriba; the machine house sits at the foot of the wall on the left bank. The reservoir can begin near Puebla de Sanabria depending on the Tera's flow, so its extent varies with the river. The crest lies at 892 m above sea level.

The water level rises and falls throughout the year as rainfall and river flow change, creating a landscape that looks different with each season. This natural variation means visitors may see the reservoir in distinctly different states depending on when they arrive.