This star- like puzzle is a cluster of 6 identical wooden blocks. Probably one of the most well known interlocking wooden puzzles.
This brain teaser is made by careful carving of two of the surfaces of each block, so that the individual pieces can interlock.
Even if you know the shape of the blocks, you will find separating them or reassembling the cluster, a very puzzling problem to tackle.
Difficulty: Level 3