Fortress of Santo Amaro da Barra Grande, Military fortress in Guarujá, Brazil

The Fortress of Santo Amaro da Barra Grande is a military installation on the southeast side of Santo Amaro Island in Guarujá that controls the shipping channel to Santos port. The complex includes fortification walls, barracks, and observation points strategically positioned for coastal defense operations.

Construction began in 1584 under Spanish rule following English corsair Edward Fenton's attack on Santos, using Italian architect Giovanni Antonelli's design. The fortification was built to prevent future maritime attacks on the region's port.

The fortress reflects Portuguese colonial military design through its stone walls and bastions that shaped the landscape. Walking through it reveals how coastal defense was integrated into daily life and territorial control during that era.

The fortress stands between Góis Beach and Santa Cruz dos Navegantes Beach, guarding the Barra Grande channel that leads to the port of Santos. The 1766 Góis Beach Battery, an advance post linked to the fortress by the so-called Spanish Gate, can be seen nearby. Parts of the site were reported in poor repair by the late 18th century, so expect weathered masonry.

The 1715 royal charter accepted Manuel de Castro de Oliveira's offer to rebuild and arm the fortress at his own expense, granting him noble status, the Order of Christ habit, an annual pension of 80$000 and a 400$000 post in Minas Gerais for his son.