Yosemite National Park, Calif.
Yosemite National Park takes up approximately 1,200 square miles of the Sierra Nevada mountain range in California. Come here to see the awe-inspiring waterfalls that the park's famous for, as well as meadows, ancient sequoias and valleys.
Favorite activities here include bird-watching, rock climbing and participating in ranger programs. Although the park's open year-round, you'll most likely need a reservation if you visit one of its 13 campgrounds between April and September. There are tent and vehicle camping options in Yosemite, and other lodging includes simple tent cabins at The Ahwahnee Hotel in the middle of the park or backcountry camping, which can be done by backpacking in or riding a horse. You're required to get a free wilderness permit if you do backcountry camping (obtaining a reservation for $5 is recommended).