23. The Grand Canyon National Park in Arizona
The Grand Canyon is considered the eighth wonder of the world by many people because of its natural beauty. Carved by the Colorado River, the Grand Canyon sees millions of tourists every year who view as much of its 277 miles in length as possible.
While the highest points in 18 miles in width, the lowest point is only 4 miles in diameter. The rock at the bottom of the Grand Canyon is over 2 billion years old. The structure became a national park in 1919, and you can camp at the canyon, as long as you have a permit.
