The first Europeans to reach this stretch of the Paraguay River were the expeditions of Captain Juan de Ayolas and his lieutenant Domingo Martinez de Irala, who founded the fort of La Candelaria on February 2, 1537. It lasted barely six months before being abandoned. Irala returned in 1542 and founded Puerto de los Reyes farther north on January 6, 1543, only to see it abandoned again by March 1544 on orders from the adelantado Alvar Nunez Cabeza de Vaca. The pattern repeated itself for centuries: forts rose, garrisons arrived, and then the jungle, the river, or hostile forces swallowed what had been built. By 1761, seventeen fortifications lined the western bank of the Paraguay River near Bahia Negra. By 1806, only thirteen remained. By 1811, all were abandoned. The land itself seemed to resist permanent occupation, yielding only to those who understood it on its own terms -- the Isir people, commonly called Chamacocos, and the Guarani-assimilated Itatines who had inhabited the area long before any European flag was planted.

In 1885, Bolivian President Gregorio Pacheco founded Puerto Pacheco on the river's right bank, aiming to incorporate these remote territories into Bolivia's domain. Paraguay responded: in 1888, Paraguayan forces occupied the port. President Patricio Escobar, with Argentine diplomatic support, defended Paraguayan sovereignty, but Bolivia reclaimed the site in 1894. The tug-of-war continued for decades. After the Acre War and the 1903 Treaty of Petropolis between Bolivia and Brazil, the situation grew more tangled -- Brazil recognized Bolivian sovereignty over the Boreal Chaco in exchange for territorial concessions elsewhere, despite having no legitimate claim south of the 19th parallel. Paraguay protested to no avail. In 1907, Paraguayan forces annexed the port again. Bolivia recovered it in 1915. This relentless back-and-forth became one of the triggers for the Chaco War, the bloodiest conflict in 20th-century South American history.

The Chaco War raged from June 15, 1932, to June 12, 1935, pitting Paraguay against Bolivia over the Boreal Chaco -- a vast territory both nations claimed and neither fully controlled. The fighting killed tens of thousands of soldiers on both sides, many from thirst and disease rather than combat, in a landscape that punished armies as effectively as any enemy. When the war ended, Paraguay held three-quarters of the disputed territory. Bahia Negra, renamed from its Bolivian-era identity, became definitively Paraguayan. The settlement that had been founded, abandoned, seized, returned, and seized again finally had a permanent national identity. On April 25, 2005, the creation of the municipality of Bahia Negra was formalized by Paraguayan law, making it municipality number 233 -- a bureaucratic milestone for a place whose history is anything but routine.

Today Bahia Negra remains one of Paraguay's most remote communities, accessible mainly by river or unpaved road. Its economy runs on cattle ranching, modest fishing, timber, and small-scale soybean and leather processing. The settlement sits at 75 meters above sea level beneath a tropical savanna climate, surrounded by landscapes that have changed little since the Isir people first hunted here. On the Bolivian border, the Rio Negro National Park harbors jaguars, giant otters, caimans, capybaras, black howler monkeys, maned wolves, and pumas -- a concentration of South American megafauna that draws increasing interest from ecotourists willing to make the journey. The Chacoan cliffs along the river's western margin support stable hamlets, while the eastern Brazilian side dissolves into the wetlands of the southern Pantanal. Bahia Negra is where the continent's wild interior persists, stubborn and largely unchanged.