Yosemite National Park - one of the first parks in the National Park Service, California's Yosemite is a World Heritage site. Its most famous scenery includes mountain peaks like Half Dome and El Capitan, Yosemite Falls, giant sequoias, and sub-alpine lakes. Adventure travel expert Matt Villano recommends Hetch Hetchy, an uncrowded area in the park’s northwest corner, for unparalleled hiking.