SAGUARO NATIONAL PARK
The Sonoran Desert is the only place on earth where you can see an actual forest of giant saguaros, those classic icons of the American Southwest. As familiar as the cacti may seem, you don't really know them until you've walked among their oddly human forms. For one thing, they're massive, standing up to 50 feet tall and weighing as much as 10 tons. Yet they do delicate work, sheltering gilded flickers, Gila woodpeckers, and elf owls. At Saguaro National Park near Tucson, Ariz., 1.6 million of them reach their arms skyward in a salute to the sun. (520) 733-5100, nps.gov/sagu.