1. Grand Canyon, Arizona, United States. The Grand Canyon is neither the largest nor the deepest canyon in the world, yet no other canyon in the world is as famous as the Grand Canyon. It is also considered to be one of the seven natural wonders on Earth. This amazing steep-sided canyon in the U.S. state of Arizona is 277 miles long, 18 miles wide and over 6000 feet deep. It is truly one of the most beautiful places you should visit in your lifetime.