These papercraft Roman siege towers were created as an educational activity to teach kids what warfare was like 2000 years ago. The accompanying literature outlines how the Romans used such towers to besiege Jerusalem in 70 AD. In addition to the siege tower, the papercraft set includes 15mm scale soldiers, a catapult, and a ballista. (Sorry, a castle to besiege is not included!) The template for the tower may be downloaded
here (right click on the images and pick "save image as"). I am impressed this model was drawn by hand! Build photos by William Webb.
Other Paper Models of Weapons of War:
CatapultTrebuchetLeonardo's Turtle TankHistoric Soldiers