Half Dome, measuring 8,842 ft above sea-level, is one of the most iconic cliffs in Yosemite, known for its sheer magnitude—a smooth granite wall rising nearly a mile above the valley. In the mid 1860s, it was deemed “inaccessible” and thought to be impossible to climb. But a decade later, mountaineer George Anderson had summited the peak. Since then, hundreds of thousands of people—all fit and experienced—have reached the summit with a strenuous, challenging hike. Others reach the peak after an exhaustive climb up the cliff’s sheer face.