15th-19th centuries. Founded on the occasion of St. Francis’s visit to the Spanish peninsula, around 1220. Built on the old parish church of St. Benedict´s, it still has the Gothic, Isabelino cloister (from Queen Isabella period). In 1862, and after the fire in the fortress, the School of Artillery was moved to this building. It contains a remarkable library on science and artillery and a museum with objects that have a great historical value.