A small archipelago in the inner Ría de Vigo, just offshore from the Redondela parish of Cesantes. The two main islands — San Simón and San Antón, connected by a bridge — have a layered history: Benedictine monks built a priory here in the 12th century, then the island served as a quarantine station for ships arriving from plague-affected ports, and later as a prison. Today it is a protected natural area, peaceful and forested, with a restored chapel and the ruins of the old monastery.
Access is by boat from the Cesantes waterfront (seasonal service, usually summer only). The island is managed by the Galician government and entry is sometimes restricted — check locally before making the trip. The walk through the grounds takes about an hour and the views back toward the Rande Bridge are excellent.