Reservoir of Santiago Nature · Vilamartín de Valdeorras, Valdeorras, Ourense The Encoro de Santiago is an artificial dam on the river Sil, in the municipality of Vilamartín de Valdeorras, built in 1968 by the company Saltos del Sil —today owned by Iberdrola— to produce electricity. It is 21 metres high and 147 metres long, and holds back an average of two cubic hectometres of water over an area of 53 hectares, which forms a wetland refuge for waterbirds, especially ducks and waders. Its sheet of water, together with the limestone, slate and quartz formations that dominate the relief of the concello, softens the microclimate of the valley floor where the Valdeorras vineyards ripen. Photo: Mayterios (CC BY-SA 4.0) What to see and do in Vilamartín de Valdeorras