If you visit Las Vegas, you will want to visit the Valley of Fire. It is about an hour away in Valley of Fire State Park, 29450 Valley of Fire Road, Overton, NV 89040.
This set of images shows just a few of the many red sandstone formations in the park. There were others, but during our visit the temperature was around over 106 degrees, so we decided not to visit of the formations that required hiking.
Another place beautiful place to see red sandstone formations is Red Rock Canyon which is located at 3205 NV-159, Las Vegas, NV 89161