This fort with four arrowhead-shaped corner bastions makes an interesting visit in the town. It was built to defend A Guarda against the Portuguese in the 17th century.
Ironically, the Portuguese captured the fort in 1665, only a year after it had been completed, and occupied it for three years. In the 19th century it served as a sausage factory. Today the interior contains some handsome Monterey pine, camellia, eucalyptus and araucaria trees, and an interpretation centre on frontier forts along the Río Miño that opens weekends only.