At IPP 28 2008 in Prague the participants received a cardboard drawing of this puzzle. I enjoyed making a few, this is the last one I have. An additional slide holder with the history of the tower
This is not a exact copy. I changed everything to make the puzzle more beautiful. Pieces consist with tongue and groove. Start: remove the piece with the compass needle.
The most difficult puzzle I have designed. The puzzle consists of 15 pieces. Some pieces can be slid under the edge. Goal: Make the numbers 1 to 9 from left to right in the frame There are different possibilities. But there is only one possibility to slide to a magic square. If you carefully open the puzzle you will see a 4. Remember that.