While visiting friends in Colorado, I got to go to the Great Sand Dunes National Park. It was very beautiful being on the Dunes and looking at the snow capped mountains above. We got to borrow someone's sled and enjoyed a ride down the dunes. The dunes went on as far as you could see, we only hiked to a few of them, which is a bit harder than hiking on trails. Rolling down the dunes was fun, until you find sand everywhere afterwards. Definitely, a place to stop if you are in Southern Colorado.
