Terracotta Army
The First Emperor developed plans to fortify his northern border, to protect against nomadic invasions. The result was the initial construction of what later became the Great Wall of China, which was built by joining and strengthening the walls made by the feudal lords, which would be expanded and rebuilt multiple times by later dynasties, also in response to threats from the north. Another project built during Qin Shi Huang's rule was the Terracotta army, intended to protect the emperor after his death. The Terracotta Army was inconspicuous due to its underground location, and was not discovered until 1974.