The quadruple nature guard structure of the first layer underground + the third layer above ground is also one of the existing 12 days guard. It takes about 15 minutes to walk from the foot of the mountain to the nature guard. The overall structure is similar to that of the city of Lou Lu (of course, the size is still inferior to that of Jilu City). The road into the castle is surrounded by layers, but the effect of propaganda posters can not be photographed on the ground.