You come upon the Black Hills, and the nearby Badlands, after traveling for many hours across horizontal plains. First you see a darkness on the far horizon. A mirage? A cloud bank?  Castles in the air? This is a magical moment in your journey — even for frequent visitors who expect the highway phenomenon. It’s wonderful to know that the magic doesn’t evaporate as you arrive. This very real place, and vastly different not just from the surrounding prairies but from every other mountain region in the world.