Reservoir of o Bao Nature · Viana do Bolo, Viana, Ourense A reservoir on the River Bibei that floods some 820 hectares and surrounds the promontory on which the town stands, turning the old town into an all but peninsula; its slopes are crowded with chestnut groves and steeply pitched vineyards. Photo: Estevoaei (CC BY-SA 4.0) What to see and do in Viana do Bolo