15. The Everglades, South Florida
The Everglades National Park in South Florida was created to protect the Everglades, which is the largest tropical wilderness in the entire country. As such, it also claims the spot of third-largest national park in the lower 48 states, after Death Valley and Yellowstone. Consisting of river, wetlands, and forests, the fragile ecosystem of the Everglades is home to over 35 endangered species.