Burr Puzzles have been found in Europe and Asia since the 18th century. Burr puzzles can take on many shapes, from the traditional burr seed shape, to balls, stars, and more. The Barrel Puzzle is made of 12 pieces, once of which is the “key”. The secret to this puzzle is finding the single key piece which needs to be removed first to release the puzzle and must be the last to go in to lock the other pieces in place. This puzzle makes a great desk toy when you need to refresh your mind and an entertaining coffee table puzzle to challenge friends and family.