The World's Most Pristine Forests
Upper Paraná Atlantic Forest, Argentina, Paraguay, and Brazil
The Upper Paraná originally measured 182,000 square miles, but with only 7.4 percent of pristine area remaining, it’s now one of the most endangered rainforests on earth. More than 90 percent of amphibians and 50 percent of plants found there are unique to the area, and according to the World Wildlife Fund, it’s an outstanding ecoregion that represents a complete range of the planet’s freshwater and saltwater habitats. But it’s also home to more than 25 million people, making it one of the most accessible—and threatened—intact forests.