You Will Never Guess The Artist(s) Behind These Underwater 'Mystery Circles'

The unsolved mystery of the 'crop circles' - Intricately carved large designs that magically appear on farms all across the world, has been plaguing scientists for centuries. Some speculate that they are the work of farmers trying to attract tourists, whilst others believe that they are alien art. But when similar creations started to appear underwater off the coast of Southern Japan, there seemed to be no explanation - logical or otherwise!