Spent a day on a recent trip hiking around the Mojave National Preserve, located about an hour southwest of Las Vegas. Among the sights in the park are the world's densest concentration of Joshua Trees, some 100+ foot tall sand dunes, and a cinder cone field with lava flows. While this preserve isn't quite as expansive or scenic as Death Valley National Park just to the north, it's an interesting diversion from the gaming tables, and can be seen in a day.