1. The Grand Canyon
Of course, we had to start off our list with one of the most popular canyons not just in the U.S. but in the entire world. They don’t call it the GRAND Canyon for nothing, with over 55 million visitors every year and 277 miles in length.
We must all thank the Colorado River for caring out the canyon’s steep sides, as it has been doing for millions of years.
Its iconic horizontal lines depict different layers of rocks, with the very bottom of the canyon being over 2 billion years old- that should put everything into perspective, time-wise!