Reservoir of Peñarroya Nature · Argamasilla de Alba, La Mancha, Ciudad Real The Peñarroya reservoir is a dam used for hydroelectric power and water supply, located in the municipal areas of Argamasilla de Alba and Ruidera, next to Peñarroya castle, within the Lagunas de Ruidera natural park. Its construction was already being considered in 1917, after the floods that Tomelloso and Argamasilla de Alba had been suffering, although work did not begin until 1947 and the reservoir was inaugurated on 23 May 1959. It stores 50 cubic hectometres over 425 flooded hectares, with a dam 44 metres high and 251 metres long at the crest, and supplies water to Tomelloso and Argamasilla besides generating electricity. Twelve kilometres from Argamasilla, downstream of the Lagunas de Ruidera, it is today much frequented for swimming and bird-watching. Photo: Luiyo from Madrid, Spain (CC BY-SA 2.0) What to see and do in Argamasilla de Alba