Fortaleza de São Francisco Xavier da Ilha de Villegagnon

The Fortaleza de São Francisco Xavier da Ilha de Villegagnon is a military fortress on Villegagnon Island within Guanabara Bay, built with defensive walls and structures in Renaissance military style. Today it houses the Brazilian Naval Academy and maintains its original architectural design.

Portuguese forces built this fortification in 1695 under Governor Sebastião de Castro Caldas after destroying the French Fort Coligny to protect the harbor. The structure played a key role in defending the area from rival powers during the early colonial period.

The fortress takes its name from Saint Francis Xavier, reflecting the deep connection between military protection and Catholic faith that mattered to early Portuguese settlers in the region. This religious naming tradition shows how spiritual values were woven into the colonial defense structures built during that era.

The area is only accessible through organized tours arranged by the Ministry of Marine, and visitors must register in advance. It is important to check current access conditions before planning a visit.

During the 1711 French invasion led by René Duguay-Trouin, an explosion in the gunpowder storage caused major damage to the original fortification. This dramatic event shaped the military history of the bay and prompted later improvements to the defenses.