* It is considerably harder to create than guard tower.
* It can't be built on top/inside/on a floor of a house or attach parts to it inside a house. You will get the message ''You cannot create that inside a building''.
* It can't be built on a bridge, but can be pushed on it after completion.
* It does not need to be built on flat ground, or unobstructed on adjacent tiles.
* Can be rotated by the owner.