The Mass Games, or Arirang Festival, is a yearly spectacle held in North Korea. Tens of thousands of participants perform synchronized acrobatics, backdrops (human billboard painting) and music. While the entire event is said to be astonishing, the human billboard performance is perhaps the most impressive. Thousands of schoolchildren depict different scenes by flipping through a book of colored pages. Werner Kranwetvogel's photo series of the 2005 games are absolutely awe-inspiring.