Church of Castiello de Jaca Monument · Castiello de Jaca, La Jacetania, Huesca Image of Castiello de Jaca, not of the place itself. The parish church of Castiello de Jaca, dedicated to Saint Michael the Archangel — whose feast day, 29 September, marks the village's patronal festivities —, stands in the upper part of the municipality. It is of Romanesque origin, from the 12th century, although it was extensively remodelled in the 16th and 17th centuries. The municipality lies on the Aragonese stretch of the Camino de Santiago, a natural gateway to the Garcipollera valley. Photo: France64160 (CC BY-SA 3.0) What to see and do in Castiello de Jaca