Simply built on a hill, initially surrounded by a wall and a moat, Forte Santo Antônio da Barra bears witness to the French presence and subsequent Portuguese consolidation in São Luís, having played a crucial role in defending the bar and controlling access to the city's port. Conquered by the Portuguese in 1615, it was renamed Santo Antônio a Barra. The current structure, which preserves the circular terrain without a moat and with remnants of the wall, dates from reforms carried out in the 18th and 19th centuries. The fort was used regularly until the end of the 19th century, when it was abandoned. In 1975, it was listed by IPHAN and later reformed between 1984 and 1991. Currently, it remains open to visitation and constitutes a tourist attraction.