Museum Collection Paradigm Wooden Brain Teaser Puzzle (Paradigm Puzzles Celtic Knot Challenge yourself, challenge your friends, with the Celtic Knot Paradigm Puzzle from Family Games This exquisite laser-cut wooden puzzle is as challenging to solve as it is beautiful to look at Once you have taken the pieces out of the wooden frame, it's devlishly difficult to fit them all back in Difficulty level 7/10, for puzzlers age 12 and over From Family Games America, the socially and environmentally responsible game and puzzle people