Let's Build Castles! Construct castles, block by block and tower by tower, as you flex your logic muscles with this beautifully crafted 3-D wooden puzzle. The challenge is to assemble the wooden blocks and towers to build one of the castles in the included puzzle booklet. The 3 towers have sticks of different length and the blocks have holes, but not always in the same direction. Where do you need to place the longest tower? 48 challenges. For one players. 3+ years.