Tower of la Casaza Monument · Tosos, Campo de Cariñena, Zaragoza La Casaza is a fortified watchtower situated above the present-day Torcas reservoir, in the municipality of Tosos, two kilometres from the village, on what was once the course of the río Huerva. It has two volumes of irregular heptagonal plan in masonry, up to three storeys high, separated by a thick wall with a window and a lowered-arch doorway, and it preserves traces of an underground passage connected to an outer walled enclosure, which suggests it may have served as a castle-refuge. At its foot lie the remains of a settlement inhabited since Celtiberian times and abandoned in the 14th century. Together with another tower, it formed part of a medieval defensive line and appears on the list of castles declared a Bien de Interés Cultural (Spain's highest level of heritage protection) of Aragón. Photo: Pompilos (CC BY-SA 4.0) What to see and do in Tosos