Here's a fortress constructed using set #8. OK, maybe not a fortress, but it's a fine structure with a view.
The inspiration for this building comes from the plan booklet that accompanies set #12. There are several fine structures found in that book.
The interesting thing about this construction is that it's modular in design.
The structure consists of three symmetric buildings combined to form one asymmetric design. The buildings could be combined in a variety of ways. This is just one possibility. If you don't like the door at the base of the tower, rotate that building a quarter turn towards the passageway.
Here's the plans. Enjoy!
