Just the feeling of standing 6,000 ft. above the roaring Colorado River will make you want to ground your feet in the dust to stabilize yourself. The Grand Canyon is our #6 AbsoluteVisit because of its impressive size and features. It's over 277 miles long and 18 miles wide. The colors and textures of the mountains are something you won't find anywhere else, mostly because they took between 3 and 6 million years to form and continue to do so even today. You should check it out for yourself.