Antelope Canyon is a canyon located in Arizona, United states and has been formed over millennia by the erosion caused by rainfall and flash floods. The running water has formed tunnels and rooms of red stone that messes with your sense of direction of not only where you are but which way is up. It is definitely a place worth visiting at some point in your life if only to imagine Indiana Jones coming round the corner looking for lost treasure and ancient artefacts.

There are more images of this awe inspiring canyon on Honestly WTF