Three Kingdoms: Starting from the Wall

The civil engineer came from a poor family in the late Han Dynasty, and the Yellow Turbans were about to kill him. Without a system and no reliance, they relied on the craft of digging trenches with rammed earth. He led the villagers to build walls and dig trenches, turning the poor villages into iron hedgehogs. The rogue bandits cannot gnaw, the noble families look down upon them, and the princes have no time to care. When he finished building the third city, the world was shocked.