Located in Yosemite, Half Dome is easily one of the most treacherous hikes in the national park, if not the world. It’s proven to be challenging by even the most experienced hikers. You’ll need a lot of preparation and determination in order to complete this hike. Each year, the Search and Rescue team responds to 100 calls from trekkers who need help, due to injury, dehydration, or getting lost. Despite the beauty of the waterfalls, it can make the trail very slippery and dangerous, so be extra careful with your footing (Trail And Summit).