The name Ybycuí comes from Guaraní and, as usually happens with Paraguayan place names, alludes to a feature of the terrain. The most widespread interpretation breaks it down into elements like 'yvy' (earth) and 'ku'i' (sand, dust, something finely ground), giving a sense close to 'sandy earth', 'sand flat' or 'land of sand'. It's a name that describes the characteristic soil of the area and that names both the town of Ybycuí and the nearby national park.
That root tied to earth and sand fits the geography of the region, in the department of Paraguarí, where the relief combines hills, diverse soils and the presence of forest and streams. For the Guaraní peoples, naming places after the characteristics of the soil, the water or the vegetation was a common practice.
As with all Guaraní place names, it's worth taking the translation with caution, since sources may offer nuances and the old phonetics admits variants. What is certain is the Guaraní origin of the name and its link with the land of the area, a trait that connects the name of the place with its own nature.
The great natural value of Ybycuí National Park lies in its protection of a remnant of the Alto Paraná Atlantic Forest, also known as the Paranaense Jungle. This ecosystem, one of the great jungles of South America, originally covered vast expanses of the eastern region of Paraguay, southern Brazil and northeastern Argentina (the same jungle of the Iguazú Falls region). It's a forest of very high biodiversity, with large trees, ferns, lianas, epiphytes and a wildlife rich in birds, mammals, reptiles and amphibians.
In Paraguay, this forest has suffered a drastic reduction due to the advance of agriculture, cattle ranching and deforestation throughout the twentieth century, until surviving only in fragments. That's why conserving areas like Ybycuí National Park takes on enormous importance: the park is one of the few accessible places in the center of the country where you can see and walk this kind of jungle, with its hills, streams and waterfalls.
The park thus protects not only a beautiful landscape, but a natural heritage of regional and global value. Its trail network, its waterfalls and its forest make it a refuge for wildlife and a space of environmental education and enjoyment of nature, as well as a living testimony of what much of eastern Paraguay was like before the transformation of the landscape.
In the middle of the jungle, among ferns and the murmur of the waterfalls, survive the pink-brick walls of one of the most astonishing factories that nineteenth-century America had: the La Rosada iron foundry. It was built in 1854 by the English engineer William K. Whitehead, hired by the Paraguayan government, and its origin is part of one of the most remarkable processes in the country's history: the modernization and industrialization promoted during the government of Carlos Antonio López (who ruled between 1841 and 1862), a continuation of the strong, autonomous state built after independence.
In those decades, Paraguay developed an ambitious program of works and its own industry, with the aim of achieving self-sufficiency and sovereignty against its neighbors. The first railway in South America, shipyards, telegraph lines and factories were built, and dozens of foreign technicians and engineers were hired, many of them British. In that context the Ybycuí foundry was set up, known as La Rosada for the color of its bricks, considered one of the first iron foundries in South America. The plant smelted iron to produce cannons, projectiles, edged weapons and agricultural tools, and symbolized the vigor of a Paraguay that sought to industrialize by its own means.
La Rosada therefore represents much more than some ruins: it's the testimony of a project of autonomous development singular in the America of its time, which made Paraguay a case apart. Its existence helps to understand why, when the war broke out, the country could sustain an enormous war effort for years, and why the foundry became a military target.
The fate of the La Rosada foundry was marked by the War of the Triple Alliance (1864-1870), the conflict that pitted Paraguay against the alliance of Brazil, Argentina and Uruguay, and that proved devastating for the country. During those years, Paraguayan industry —including the Ybycuí foundry— turned to the war effort, smelting iron and making cannons, projectiles and weapons to sustain the war.
Precisely because of its strategic importance, La Rosada became a target of the allied forces. In May 1869, the Triple Alliance troops reached the foundry and bombarded it: the attack destroyed the establishment and left hundreds dead —sources cite the figure of about 231 deaths, among them Captain Insfrán and the workers and convicts who sustained production. It was one of the many episodes in which the war ravaged Paraguay's productive infrastructure. The destruction of La Rosada symbolizes the end of that industrial project and, more broadly, the catastrophe the war meant for the country, which lost much of its population and resources.
After the war, the foundry's ruins remained in the forest as a mute testimony of that past. Only from 1973-1974 were they recovered and enhanced as a historic site within Ybycuí National Park, and since 1975 the La Rosada Museum operates there, with a model of the original foundry and a replica of the famous Christian Cannon. Thus, the memory of industrialization and war became integrated into the protected natural heritage, and today the museum and the ruins let the visitor glimpse that decisive page of Paraguayan history.
Over time, the Ybycuí area went from being a site tied to industry and war to becoming a space of nature conservation. Ybycuí National Park was created on May 16, 1973, by Decree No. 32,772, with an area of about 5,000 hectares, and is among the first national parks of Paraguay. Its creation responded to the need to protect the valuable remnant of Atlantic forest that survived in the region, at a time when deforestation was advancing strongly over the Paraguayan jungle, and at the same time to safeguard the historic ruins of La Rosada.
Since then, the park combines two missions: the conservation of its ecosystem —with its hills, streams, waterfalls, flora and fauna— and the preservation and enhancement of its historical heritage, represented by the ruins and the museum of the La Rosada foundry. That double condition, natural and historical, makes it a singular place within the country's protected-area system.
Today Ybycuí National Park is, moreover, one of the most beloved and visited nature destinations of central-southern Paraguay, both for enjoying the waterfalls and the trails and for learning about the country's industrial history and the importance of conservation. Its management, in the hands of the environmental authorities, seeks to balance tourist and educational use with the protection of the forest, recalling that it's a fragile and valuable heritage that should be visited with respect.