The UCS bases are defended by three structural types. Small Towers, situated right inside the base, provide anti-aircraft protection. In mountainous regions, where there's not much space, the Large Tower is the main defense building. This is normally equipped with a heavy plasma gun to repel enemy attacks. On the plains, bases are usually protected by Fortresses, heavily armored structures equipped with 4 different guns. Conventional units will find these almost impossible to penetrate.