Sancti Petri Castle is a historic fortress located on a small island near Chiclana de la Frontera. The castle dates back to the 13th century and offers stunning views of the surrounding area. Visitors can explore the castle's interior, which houses a small museum showcasing the history of the region. The island itself is also worth exploring, with its picturesque landscapes and beautiful beaches. Sancti Petri Castle is a great attraction for history buffs and those looking for panoramic views.