These stationary cannons are positioned at various places north of City Hall, protecting the path to Clozer Woods where Teisel is trying to dig his way into the ruins.

The Gun Batteries are able to rotate all around in order to get a good shot at their target. However, they are slow to move, slow to fire, and have weak armor. Unless standing still and thus making an easy target for them, it's quite easy to avoid the attacks from these machines.

Later on, a few more are positioned down south in the Cardon Forest area.