The Fortress Walls used by the Allies and the Soviets during Third World War were the successors of the Second World War Concrete wall. During the Psychic Dominator Disaster, the Soviet traitor Yuri also used these walls in his arsenal (known as Citadel Wall). For all intents and purposes, Yuri's walls were similar to the Allied and Soviet one, except height and shape, and that if they are damaged, they need to be sold and be rebuilt instead of simply being rebuilt, as the Allies and Soviets did.