As the earth’s population and world travel grow, some favored eco-travel locales struggle to protect the natural environment. The Gunung Leuser National Park remains a place to experience a stay in an untouched jungle.-By PAMELA GRANT

The Gunung Leuser National Park is one of those spots that is increasingly rare to find. The UNESCO-listed natural laboratory on the island of Sumatra has been conserved to protect some of the most endangered species in the world. Though many are elusive, you can expect to see orangutans in their natural habitat, along with gloriously colored birds and luscious forests. As if more is needed to attract the eco-traveler, this jungle sti....