Trinidad and Jesús
Set atop a lush green hill 28km northeast of Encarnación, Trinidad is Paraguay's best-preserved Jesuit reducción (settlement). You can hire a Spanish-speaking guide near the gate (tip generously) or hang around until dark for the atmospheric light show, which projects a history of the site onto the walls of the ruins.
Itaipú Ecological Reserves
As a result of the catastrophic flood damage caused by Itaipú, the dam company was obliged to set up a series of eight private reserves that now protect the last remnants of the Alto Paraná Atlantic Forest. Three of the most interesting are Refugio Tati Yupi, Reserva Itabó and Limoy. Refugio Tati Yupi, 26km north of Ciudad del Este, is the easiest to visit.
Mbaracayú Biosphere Reserve
Singled out by the WWF as one of the 100 most important sites for biodiversity on the planet, the 70,000 hectare Mbaracayú Biosphere Reserve is one of Paraguay's natural treasures. Consisting of pristine Atlantic Forest and cerrado (savanna) in approximately equal quantities, it is home to more than 400 bird species and a range of large mammals.
Central Chaco Lagoons
A series of ephemeral saline lakes that form in the area to the east of Loma Plata have been declared an 'Important Bird Area' because of their importance for migrating birds. Though individual lagoons may be dry for several years before filling after a good rainstorm, the birds somehow find them.
Fortín Boquerón & Fortín Toledo
Fortín Boquerón is the site of one of the decisive battles of the Chaco War (1932–35). There is an excellent museum as well as a graveyard of the fallen and a gigantic monument constructed from the original defenses and trenches. Look for the hollowed-out palo borracho tree used as a sniper's nest.
Northwestern National Parks
Once the realm of nomadic Ayoreo foragers, Parque Nacional Defensores del Chaco is a wooded alluvial plain; isolated Cerro León (500m) is its greatest landmark. The dense thorn forest harbors large cats such as jaguars and pumas, as well as tapirs and herds of peccary.