Impossible Square

This amazing puzzle is a real head-scratcher, with a very clever solution to boot! The Impossible Square puzzle comes with 16 wooden pieces arranged inside an elegant wooden box, as well as a red wooden square. It looks as if there is no way to stick this additional red piece in there with the other pieces inside the wooden box, but that is exactly what you are required to do- rearrange the puzzle's pieces so that all of them, including the red square, fit inside the frame!

Although this one seems downright impossible at first glance, this puzzle is solvable indeed, it has one of the most elegant solutions around!
Comes complete with a wooden box and a lid to place all the pieces for safe-keeping.