Patented in America in 1975, the somewhat swirled pieces of this puzzle by Eldon Vaughn must be taken apart and then put back together. I once found a smaller version of this puzzle about twenty years ago in America, but considered it impossible to solve at the time. We have made a new version maintaining the difficulty of the original and licensed it for the cast Cast Puzzle series. This is without a doubt among the most difficult of all puzzles. The key word is 'Twist'. Don't use too much force...the pieces should just slide apart.