National Historical Museum

Before this complex ever displayed paintings or royal carriages, it spent three centuries preparing for combat. The point of land jutting out into Guanabara Bay began its military life back in 1603 with the Fortress of Santiago. It guarded the bay, pointed cannons across the water, and kept hostile ships away from the colonial harbor.

Over time, coastal defense became a massive industrial undertaking. In 1762, the royal administration built the Casa do Trem to hold weapons, carriages, and gunpowder. Two years later, that expanded into the Arsenal de Guerra. This was not a tranquil depot. It was a loud, smoky compound of iron forges, foundries, and carpentry shops, where hundreds of mechanics and enslaved laborers repaired cannons, built gun carriages, and manufactured equipment for the army.

That military purpose did not fade quietly when colonial rule ended. The Arsenal of War operated right on this ground throughout the imperial era and well into the Republic. Military personnel did not pack up their operations until 1902, when the institution was reorganized and moved elsewhere in the city.

So when we walk these corridors today, we are not simply visiting an institution that collects artifacts from the past. We are standing inside a machine built to wage war, one that was only converted into a hall of memory after the soldiers finally cleared out.