Zhonghua Gate, also called the South Gate, is the largest gate and the best preserved one gate in the Nanjing City Wall. Because of a legendary story of burying a Treasure Collecting Pot during the construction of the gate, it was also called as "Treasure-collecting Gate". The gate from south to north is 128 m in depth, 118.5 m in width wide and was built with huge granite rectangular stones and bricks. Besides the normal facilities of a typical city wall like the compound, the draw bridge, the watching towers and ramparts, the most particular unique structure of this city wall gate was its special cave where soldiers were would hide. Inside the gate are 27 caves, each could capable of hide hiding more than 100 soldiers. Despite all these mentioned above, it also has three successive barbicans and four successive arches that which are linked. up. It is rare to have such large-scale and carefully-designed gate in the world.