White Sands National Monument

It's called White Sands National Monument, and Christopher expected little more than a statue.  (I don't know what Xingxing expected) But what we found was nothing less than  the largest gypsum sand desert in the entire world.
The white, gypsum sands really are white, spectacularly so. They are arranged in undulating dunes which are constantly on the move, traveling as  much as 38 feet in a single year.  The gypsum comes from the surrounding mountains.  It is leached out by the rain, and flows down the sides of the mountains to collect in pools, where it forms soft crystals as the pools dry out.  The crystals are light enough to be blown about by the wind, and when this happens, they break up into smaller and smaller particles, eventually forming fine, white sand.
People climb the dunes and slide down them and take photographs, but I suspect it wouldn't be all that difficult to get quite lost here, and quite quickly.  Once you're out of sight of the road, it all looks pretty much the same.  Because the dunes are continually moving, the road has to be plowed regularly.
Prevailing winds blow the sands across the flat basin and gradually, as the winds grow weaker, sand accumulates and grasses and other vegetation take root, forming a boundary of sorts. Animals live here -- mostly small, and mostly nocturnal.  We didn't see any of them.
Christopher climbed a dune to see what was on the other side -- more dunes -- but Xingxing and I were less adventurous, sticking to the boardwalk which has been constructed to give visitors a feeling of the desert without the risk of losing themselves in the white vastnesses.
Driving along past all these huge, white mounds of sand was a bit unworldly -- which I guess was a good preparation for our next stop: Roswell, and the International UFO Museum.