Fort Prince of Beira

Forte Príncipe da Beira is a colonial military complex in Costa Marques on the banks of the Guaporé River, near the border with Bolivia. The fortification consists of four angular corner bastions linked by thick stone walls that enclose a large central courtyard, once used as a parade ground and assembly point for the garrison.

Between 1776 and 1783, the Portuguese crown built the fortress as a defensive line against Spanish advances from western colonial territories. The garrison remained active into the 19th century and lost its military function only after Brazil's independence and the stabilization of the border region.

The name honours Dom Pedro Carlos de Bragança e Bourbon, a Portuguese prince, and reflects the monarchy's claim over these remote borderlands. Visitors see European military design blended with tropical building methods, particularly in the vaulted chambers and open courtyards that allowed air to circulate in the humid forest climate.

The site lies several kilometers outside Costa Marques and is reached by an unpaved road that can become difficult to navigate during heavy rains. Those exploring the walls and bastions should wear sturdy footwear, as the ground is uneven in places and overgrown with vegetation.

The complex was one of the few Portuguese fortifications built far from the Atlantic coast in Brazil's interior. Construction required transporting heavy stones and brickloads over hundreds of kilometers through dense rainforest and along the river, a logistical achievement for the time.

Location: Costa Marques

Inception: 1783

Part of: Conjunto de Fortificações do Brasil, Forts of Brazil

GPS coordinates: -12.42722,-64.42306

Latest update: December 5, 2025 22:25