Umia River Nature · Caldas de Reis, Caldas, Pontevedra It crosses the concello from south to north on its way to the ría de Arousa and shapes the landscape of the spa town, with riverside woods, mills and bridges; its waters also feed the pools and falls around Segade. It rises in the parish of Aciveiro, in Forcarei, from the joining of several mountain streams, and then runs through eight concellos before flowing into the ría de Arousa, at the Ponte da Barca de Cambados, after a course of about 70 kilometres and a basin of 404 km². As it passes through Caldas de Reis, already in confined stretches, it forms a waterfall at the site of Cesar before entering flat ground on its way to the final marsh, an environment rich in migratory birds and local legends, such as that of the "ponte dos padriños" of Ponte Arnelas. Photo: Luis Miguel Bugallo Sánchez (http://commons.wikimedia.org/wiki/User:Lmbuga) (CC BY-SA 3.0) What to see and do in Caldas de Reis