5 must-visit national parks in the USA that are also UNESCO World Heritage Sites

UNESCO Inscription: 1983
The most biodiverse national park in the USA, Great Smoky is noted for its misty peaks, dark forests, and rich cultural heritage. The park attracts the highest number of visitors of any U.S. national park as it is home to over 19,000 documented species. But scientists believe there are tens of thousands more that remain hidden.
The park protects some of the oldest mountains in the world and is dotted with some ancient trees. Some of the star attractions include Cades Cove and Clingmans Dome, among others. The place turns otherworldly during the fall. It is a kaleidoscope of red, orange, and gold, drawing leaf-peepers from across the globe.