Why it is worth the drive
Great Sand Dunes National Park sits in the San Luis Valley in southern Colorado, with the Sangre de Cristo Mountains rising right behind the sand. The dunes are the tallest in North America, and there are no set trails on them. You just pick a ridge and start climbing.
Timing your visit
In late spring and early summer, snowmelt feeds Medano Creek, which runs across the base of the dunes. On a good year it turns into a shallow, rippling stream that families treat like a beach day.
In summer the sand surface gets extremely hot by midday. Climb in the early morning or the evening, and wear closed shoes.
Stay for the stars
The park is a certified dark sky park, and on a clear moonless night the Milky Way is easy to see with the naked eye. Camping in the park or nearby lets you take it in without a long drive back in the dark.