Hourglass Puzzle - Hanayama Cast Puzzle
The Hourglass puzzle is a very difficult puzzle that is made of 4 cast metal pieces. Each piece of the puzzle is engineered precisely to interlock in a seamless way. There are sequential tricky movements that need to be discovered to solve the puzzle. The Hourglass cast puzzle was designed by JinHoo Ahn and is considered one of the hardest puzzles in the Hanayama collection.