The chestnut sierra Nature · Vallejera de Riofrío, Sierra de Béjar, Salamanca Image of Vallejera de Riofrío, not of the place itself. The chestnut accounts for close to sixty per cent of the trees in the municipal district, accompanied by oaks, ash and beech. The municipality, at 1,240 metres above sea level, forms part of the Sierras de Béjar y Francia biosphere reserve declared by Unesco. Photo: Javi garci garci (CC BY-SA 3.0) What to see and do in Vallejera de Riofrío