16-mile (RT) strenuous hike from the Happy Isles Nature Center to the top of Half Dome and back. During its 4,800 elevation gain, the trail passes two wateralls (Vernal and Nevada Falls) and meanders through a lovely forest before finally arriving at the back of Half Dome. From there the trail winds steeply up gravel boulders to a set of steel cables that enable you to climb the slick and steep rock the final 400 feet to the top of Half Dome.