Basic Walls is an Empire defense building in Total War: Warhammer. Up-righting wooden shafts to create a stockade or a low stone wall may hinder the enemy, but will not keep them out.
Larger hamlets, villages and small towns will have some barrier in place to protect them from the wilderness. Of course, a basic wall must be manned to be effective or else the foe will just climb right over - slowing them down but not stopping them