Walk far enough along the shaded trails of Ybycuí, past the rosewood and cedar and the white noise of falling water, and you come upon something the forest never made: the brick and iron skeleton of a foundry. This is La Rosada, and the quiet that surrounds it now is a kind of irony. A century and a half ago this clearing roared with furnaces and hammers, casting the cannons that a small nation hoped would keep it alive. Then an army came, and the roaring stopped.
Ybycuí National Park protects a serene stretch of subtropical woodland in southern Paraguay, the kind of place best visited in the rainy season when the streams run full. It is famous above all for its waterfalls, the saltos, where clear freshwater spills into pools cool enough to swim in. Salto Mina, Salto Yruvu Kua, Salto Kuñatai, and the twin falls of Salto Mbocaruzu are strung together by trails that wind beneath the canopy. The forest holds guatambú, black laurel, cancharana, cedar, and rosewood, and shelters birds and animals patient watchers may glimpse. With official campsites near Salto Mina, it makes an easy overnight escape from Asunción, about three hours away by road.
La Rosada was among the first iron foundries in South America, established in 1850 and operated by English engineers as part of President Carlos Antonio López's ambitious campaign to industrialize Paraguay. Here the young republic forged the hardware of a modern state: tools, components for its riverine navy, and, increasingly, weapons. When the catastrophic War of the Triple Alliance engulfed Paraguay in the 1860s, the foundry's cannons and munitions became vital to a nation fighting Brazil, Argentina, and Uruguay all at once. Its importance was also its doom. In 1869, advancing Brazilian troops overran La Rosada and destroyed it, silencing one of the country's proudest engines of self-reliance.
What the soldiers left has been partly restored, and the old workers' quarters now house a small museum displaying the things the foundry once made. The contrast is the whole point of a visit: a place built for fire and industry, reclaimed by green stillness and the sound of water. The war that ended La Rosada was among the deadliest in the history of the Americas, and it gutted Paraguay's population, particularly its men, on a scale the country took generations to recover from. To stand among these ruins is to feel that loss without a lecture, in the gap between what this forge was meant to build and what became of the people who worked it.
Ybycuí rewards the effort it takes to get there. From Asunción, the drive runs south on Route 1 to the town of Carepegua, then onto Route 18 toward the park, the pavement giving way to rough dirt tracks that the wet season can turn punishing; inside the park, only sturdy vehicles really cope. Buses run from the capital's main terminal toward Ybycuí and Salto Mina, leaving the small town of Ybycuí some 20 kilometers shy of the entrance. The reward is a park that asks for patience and a guide's eye. Birdsong fills the canopy, animals keep to the shadows, and the waterfalls reveal themselves one trail at a time. Camp near Salto Mina and you can stay the night where the foundry's furnaces once burned, the forest dark and close, the falls never quite going silent.
Ybycuí National Park lies at 26.10°S, 56.84°W, roughly 150 km south of Asunción by way of Routes 1 and 18. From the air the park reads as a block of denser forest rising from surrounding farmland, threaded by streams that feed its waterfalls; the village of Ybycuí sits about 20 km from the park entrance as a navigation cue. The nearest international airport is Silvio Pettirossi International at Asunción (ICAO: SGAS). Recommended viewing altitude is 3,000–6,000 feet AGL to appreciate the forest-and-clearing mosaic and the stream courses; haze can build over the woodland on hot afternoons, so morning light gives the cleanest view.