The tower of doom is my current project, it takes quite a lot of time. The map is from yesterday so i actually build more of it already. It has to round layers (and the top will be different) and it will have small floating towers on the side.
The 2 layers are quite useful, i can use them as secret passages for hidden rooms, and i want to use them to place redstone wires to control doors, alarmsystems, trap, etc.