This is another one of my entries for the Colossal Castle Contest at www.classic-castle.com. It is a walled in working trebuchet for defending the people inside the castle walls. A trebuchet has one of the longest ranges for a seige weapon, so most attacking catapults can be destroyed by the trebuchet before they can breach the castle wall. This trebuchet does work, and throws a LEGO brick pretty far. It is weighted with pennies. It is also on a turntable, hence the wheel in the back. It fires about 6 - 8 fet, but I got it to fire 10 feet off of my shelf. However, when it is fired, the COG of the trebuchet is shifted forward, becasue of the weight and momentum of the arm, so you kindah have to reset the treb each time you fire, or it will break.