Zijincheng, also known as the Forbidden City, is largest and best-preserved ancient palace-type wooden building in China, built without using a single nail. Since it was 1420, has served palace where emperor lives works. Almost 600 years old, gone through two dynasties (i.e., Ming Qing (AD 1368–AD 1912)) 24 emperors. It survived more than 200 devastating earthquakes throughout its history, stil...