POSADAS — A million tourists a year now visit the Iguazú Falls, where 275 distinct cascades, nearly 2 miles wide, separate Argentina’s Misiones province from Brazil. The sound and fury created as the Río Iguazú pours over 265-foot-high basalt ledges are overpowering, the visceral impact one of South America’s most compelling experiences. It’s hardly surprising that such a sight has long overshadowed the attractions of the toucan- and butterfly-filled jungle that surrounds the falls, but that is beginning to change.

Misiones, named for the mission settlements established by the Catholic Church’s Jesuit order during Spanish colonial times, juts like a finger far into Brazil and Paraguay. Bounded to the west by the Río Paraná and to the east by the Río Uruguay, its forested terrain and sheer remoteness have long complicated contact with the rest of the country.