Grand Canyon, Nevada. Can't wait for the kids to get older so we can hike. I don't remember going as a kid, but apparently we did! I do remember going in my early 20's and most especially for our 10 year anniversary taking a helicopter to the bottom for a champagne lunch. Goes down as one of the most amazing adventures of my life.
The Grand Canyon National Park Unique combinations of geologic color and erosional forms decorate a canyon that is 277 river miles (446km) long, up to 18 miles (29km) wide, and a mile (1.6km) deep. $25 per private vehicle entrance fee, or $12 per person on foot/bicycle. The South Rim is open all year while the North Rim is open May 15 through October 15.