the brain66 puzzle
The Brain66 Puzzle is a classical tiling puzzle. A two-dimensional packing problem in which a number of flat shapes have to be assembled into a larger given shape. The Brain66 Puzzle is the hardest tiling puzzle of all time. It is not possible to create a different puzzle with the same number of pieces which is harder to solve.
There are 66 pieces in twelve different shapes, which can be mirrored and rotated. The shape of the Brain66 Puzzle is an equilateral triacontagon (thirty-sided polygon) with a rotational symmetry of order ten. The Brain66 Puzzle is solved, if the triacontagon shape is completely tiled by all 66 pieces without overlaps and without gaps.
A beautiful and intelligent masterpiece with a unique geometry.