The Castillo de Tou stands as ruins on the Peña Cotón hill near Aínsa-Sobrarbe in Huesca province, part of a larger archaeological complex next to the Mediano reservoir. Likely constructed in the late 10th or early 11th century, it represents one of the Christian fortifications built along the Cinca River to defend against Muslim raids from the south. The ruins occupy the highest point of the site, adjacent to the remains of the fortified settlement of Tou. Access to the castle requires a half-hour uphill walk from the vacation center in nearby Morillo.
