C184 Push the waves forward

Thus, after I leave, I need you to expand the Xuanyuan City to form an outer city. The walls don't need to be constructed entirely with bricks and stone, they need to be tamped inside, since digging into the soil of the moat is useless, the outer layer can be wrapped with brick and stone, and outside the outer wall of the outer city, I can dig out a 300 meter long, 100 meter deep river