Japanese Interlocking Ladder PuzzleThe Interlocking Ladder Puzzle is based on the "Japanese Crystal Puzzle" originally designed in Japan circa the 19th century. This stunningly ornate and intriguing device is one of the most challenging units in our entire interlocking puzzle collection. Symmetrical, multifaceted, and celestial, the structure is made out of 51 non identical, interlocking bars. Each piece is precisely cut so they interlock perfectly to make a solid structure. Similar to