Fuerte de São Joaquim do Rio Branco

Fuerte de São Joaquim do Rio Branco sits where the Rio Branco and Tacutu rivers meet, displaying the solid stone walls characteristic of Portuguese border fortifications. The ruins reveal the original layout and give insight into the colonial military design used throughout the Amazon region.

Built between 1775 and 1778 under Captain Phillip Sturm's command, it protected Portuguese territorial claims against Spanish and Dutch competition in the northern Amazon. The fortification marked one of Portugal's first military bases in this remote region.

The name references Saint Joachim and reflects the religious meaning Portuguese colonizers attached to their military outposts. You can still observe how religious symbols and defensive purposes merged in the layout of the structures.

The site is accessible via the town of Bonfim and sits along the river banks where you can see the surrounding landscape clearly. Sturdy footwear is recommended since the ground is rough and the paths are uneven.

The fortress mortar was made from local clay, showing how builders cleverly used regional materials available to them. This technique allowed the structure to endure despite harsh conditions in the remote Amazon region.

Location: Bonfim

GPS coordinates: 3.04056,-60.48694

Latest update: December 11, 2025 11:08