The incredibly grueling Pinnacles jungle trek at Gunung Mulu National Park in Sarawak, Malaysian Borneo. It's only 2.4km / 1.5 miles to the summit, but to get there you have to climb up 1.2km / 0.75 miles of jungle madness.
Put on your Indiana Jones hat, it's time to go on a crazy adventure! You immediately know you're in for it when the trail beings with a sheer rock wall and a dangling rope. From there on, it's a 7-8 hour roundtrip of scrambling over jungle roots, scaling limestone walls, climbing slippery ladders, sweating through every last inch of your clothing, balancing on narrow metal beams across crevasses, avoiding leeches and pit vipers (snakes! I hate snakes!), and earning every... single... last... step of the hike with your blood, sweat, and tears.
The reward: a stunning view of the aptly named Pinnacles, natural giant limestone karst formations protruding like skyscrapers above the jungles of Borneo.