Great Sand Dunes National Park, near Alamosa, Colorado, is one pretty impressive place. Eons of natural and geologic forces have conspired to dump trillions of tons of sand at the foot of the San Juan Mountains. Definitely worth a visit. Learn more at the Sand Dunes Website.
There are two things I absolutely love about this photograph. The first is the person in the middle of the frame, who you can just barely see. This helps show how large these dune fields are. The second is that perfectly ovular hole in the clouds. That's not editing. That was there!
Hope you enjoy the photo.