Mondón Spa Activity · O Bolo, Valdeorras, Ourense Image of O Bolo, not of the place itself. Thermal establishment opened in 1903 in the concello of O Bolo to make use of a spring of ferruginous waters, in a remote valley of the upper Bibei to which spa-goers came from all over the comarca. Photo: Estevoaei (CC BY-SA 4.0) What to see and do in O Bolo