Hawaiian for “white mountain,” Mauna Kea is somewhat of a contradiction, as it is actually a volcano that only occasionally gets enough snow for skiing and boarding. Be warned: only those looking for extreme adventure and novelty should make the trip; this is not your average ski vacation. There are no lifts, there is no resort, and the snow is completely natural and ungroomed. You’ll need a four-wheel-drive vehicle to get you to the top of the mountain which sits at almost 14,000 feet above sea level. Once on top, the air is extremely thin so prime physical fitness is essential for a safe trip down. Add to the mix a strange snow texture, steep sections and snow cover that sometimes ends abruptly. You won’t want to fall on this run, as there is no grass under the thin layer of snow—just hardened lava.