Built by the Templars in the early 14C, the castle was later modified by Benoît XIII. The lower section is occupied by the barrel-vaulted guardrooms and stables. The group of buildings around the parade ground include the vast church, with its pointed vaulting, and the so-called "conclave room". The study of this learned pope, an expert in ecclesiastical law, is located in an isolated tower. From the terrace, there are fine panoramic views of the village of Peñiscola and the coast.