Iguazu Falls aren't northern Argentina's only UNESCO World Heritage Site. History buffs may be tempted away from the falls by the Jesuit Missions of the Guaranis, a cluster of well-preserved ruins of reducciones, or settlements, built here by the Catholic order in the 1600s. There are four of these beautiful walled cities to explore: Sao Miguel das Missoes, in Brazil, and Argentina's Nuestra Señora de Loreto, Santa Maria Mayor, and San Ignacio Mini, the finest of them all.
San Ignacio Mini was originally founded in 1611, and moved to the current location in 1696. Hewn from beautifully carved red sandstone, it was designed to both protect and convert indigenous Guaranis, primarily children, to Catholicism. The remains of a magnificent church, as well as sleeping and living quarters, can all be explored on a guided tour.
After the Spanish Empire evicted the Jesuits in 1767, the recciones were systematically destroyed and forgotten. The ruins, rediscovered in 1897, have been partially restored. A nightly light show spectacular tells the story of Guarani life inside these crumbling walls.
The ruins are located about five hours from Puerto Iguazu by bus, not ideal for a day trip. Private tours in faster vans are a better option, and are often combined with the amethyst fields at Wanda Mine. If you aren't on a guided tour, note that these arrive en masse from Iguazu in the early afternoon.