Grío River in Santa Cruz de Grío Nature · Santa Cruz de Grío, Valdejalón, Zaragoza Image of Santa Cruz de Grío, not of the place itself. The Grío river is a tributary of the Jalón that rises on the northwestern slope of the Atalaya peak, in the Sierra de Algairén, at 1,164 metres above sea level, and runs for 41.4 kilometres before flowing into the Jalón near Ricla, at 358 metres. Its basin covers 193 km² and contributes an annual average of 18 cubic hectometres. It flows through the municipalities of Codos, Tobed, Santa Cruz de Grío, the depopulated Aldehuela de Grío and La Almunia de Doña Godina. As it passes through Santa Cruz de Grío it receives the intermittent waters of the Val and Valdelaparra ravines. Photo: Jaime Calatayud (CC BY-SA 4.0) What to see and do in Santa Cruz de Grío