A great place to go to in New Mexico. It's a beautiful landscape of sand dunes, and the sand is made of gypsum, so it's stark, gleaming white. There isn't much hardpan, it's mostly soft and mushy, so it's a lot of fun to walk on and run down the dunes. You won't see much plant life there, aside from the occasional yucca. The size of the monument is 142,987 acres.
Relatively close to Roswell, IIRC. There is a hiking trail that leads for several miles from one point in the dunes to another on the other side. The entire hiking trail is not for the fainthearted.
I visited there a couple years back, taking a camera with me, thinking I would be like Ansel Adams. Let's just say I won't be quitting my computer job to become a photographer anytime soon. | 
