White Sands: Alien Dunescape
Alamogordo, New Mexico
Snapshots taken at White Sands make it look like a winter wonderland, but the "snow" is actually crystals of white gypsum. They never melt, and the gypsum also doesn't get hot, like sand. Yet air temperatures on the towering dunes can climb to over 100 degrees on sunny summer afternoons. Tourists who wander off the marked trails, or who don't bring enough water, have died of sunstroke and dehydration. On bright days, without eye protection, you can go snow blind.
Unlike most places of natural wonder run by the National Park Service, White Sands encourages goofy interaction with its environment. At the Visitor Center, tourists can buy snow saucers for dune sledding -- an odd thrill in July -- and the sweeping, otherworldly vistas are shutterbug's dream for science and sci-fi nerds. "Look at me! I am watching for Imperial storm troopers on the ice planet Hoth!"
The U.S. government uses most of White Sands' 275 square miles -- the largest gypsum dune field on Earth -- as a missile testing range, leaving only a small section for tourists. This is actually a good thing, as it makes the park a quick and easy destination. There's one way in, one way out, the distances you have to travel are relatively short, and the dunes are conveniently off of the parking lots next to the one main road.
In other words, you can be walking on an alien moonscape at noon, hop in your car, and 30 minutes later be in the city of Alamogordo eating a green chili cheeseburger.
White Sands is occasionally closed during rocket launches, and there are many signs in the park warning visitors not to pick up anything metallic. It might explode.