Fortaleza de Santo Antônio de Ratones, constructed beginning in 1740 on Ilha de Ratones Grande, served as the third defensive vertex in Brigadier José da Silva Paes' triangular fortification system designed to protect Santa Catarina Island's northern entrance. The stone fortress features several significant buildings including the Portada, Fonte d'Água, Commander's House, Officers' House, and Powder Magazine. After losing military function in the 19th century, it became a health center during epidemic outbreaks before being listed as a National Historic and Artistic Heritage site in 1938. Today, visitors reach this well-preserved fort via maritime tours from nearby beaches, experiencing both the architectural heritage and surrounding natural beauty.
