Landscape of the Isuela Valley Nature · Calcena, Aranda, Zaragoza The Isuela rises in Beratón (Soria), at 1,616 m on the southern slope of the Moncayo, enters Zaragoza and flows through Purujosa, Calcena, Trasobares, Tierga and Mesones de Isuela before joining the Aranda. In Calcena it forms a waterfall reached by crossing a stone bridge, and together with the Aranda it shapes the valley that separates the sierras de la Virgen, del Tablado and de la Nava Alta. Photo: Pompilos (CC BY-SA 4.0) What to see and do in Calcena