São Marcelo Fort

São Marcelo Fort is a circular fortification set in All Saints Bay, extending roughly 300 meters from the mainland, built with thick stone walls and defensive turrets. The structure contains concentric rooms arranged around a central courtyard, a design that gives the fort its distinctive shape.

The fort was built between 1608 and 1623 by the Portuguese to defend Salvador against Dutch invasions. It later served as a prison during political conflicts before receiving national monument status in 1938.

The fort takes its name from Saint Marcelo, linking it to Portuguese religious traditions established during colonial times. Local fishermen and boat operators continue to work these waters, keeping alive the maritime practices that have shaped this place for hundreds of years.

The fort is reached only by boat departing from Centro Nautico near Mercado Modelo. Tours run Tuesday through Sunday, so plan your visit for these days and prepare for a short boat ride to reach the offshore location.

This is Brazil's only circular military structure, inspired by European models like Castel Sant'Angelo in Rome and São Lourenço do Bugio in Portugal. The unusual design allowed for more effective defensive lines and made the fort an architectural experiment of the colonial period.