Turn to the army cave! The small highlights of the Rucheng site, the source of the saying "Cao Cao's soldiers are countless", is also the materialized version of the ancient famous plan "Jin Xuan shelling". In fact, it is a twisty and dark road, from Linqu County Tongquetai directly to Cixian County to talk about Wucheng, the total length is 6 kilometers, and currently only 83 meters. It is said that later, when excavating a section of the city wall in Yucheng, he found the secret road. How much did Cao Cao like this kind of facilities?