5. The Kokoda Track The Kokoda Trail is one of the world’s great treks, taking enthusiastic, fit hikers on a journey that will challenge and inspire. Follow the path where Australian and Japanese armies engaged in bitter warfare during the early days of World War II. Papua New Guinea’s unforgiving, rugged wilderness provides an unforgettable backdrop for a life-changing experience. 60 miles long, the Kokoda Trail takes trekkers through mountainous country that boasts incredible rainforest and jungles that are home to rare species of ferns, orchids and birds. Sparkling mountain streams and steep valley climbs provide breathtaking contrasts throughout the trek. In 2009, 13 people died in a plane crash en route to the trailhead, and four more hikers died on the trail, which takes up to 11 days to complete. They faced malaria, extreme heat, frigid nights, and daily bone-soaking afternoon rains. The route itself has been called a StairMaster in a steam room, with ankle-deep clay muck,...