Old Tower of Río Monument · San Xoán de Río, Terra de Trives, Ourense Image of San Xoán de Río, not of the place itself. Remains of a medieval fortress whose stones ended up reused in the building of the castle of Castro Caldelas, a common fate for towers pulled down in the revolts of the 15th century. Photo: xolopi (CC BY 3.0) What to see and do in San Xoán de Río