-The Defensive Wall serves as the primary defense line, shielding your command center behind it. 

-Upgrade it to increase the capacity of defensive weapons you can reduce and boost your defense points.
-If your base gets attacked, it will catch fire, gradually reducing defense points as long as the base burns. Click on the wall and select "Defense" to extinguish the fire and to check the remaining defense points and increase them.
-Once the defense points of the wall reach zero, your base will be relocated randomly to another spot on the map.