Viewpoint of el valle del Aranda Nature · Illueca, Aranda, Zaragoza Illueca, capital of the comarca of the Aranda, sits in the valley of the river Aranda amid the surrounding mountains, 89 km southwest of Zaragoza. The municipality, known for the castle-palace of the Papa Luna, preserves caves, old hermitages and several natural viewpoints offering wide views of the valley. Photo: Willtron (Wikimedia Commons) (CC BY-SA 3.0) What to see and do in Illueca