The large structure built to protect the Chinese Empire from invasions is the Great Wall of China. Construction began as early as the 7th century BC and continued over several dynasties, particularly during the Ming Dynasty. The Great Wall served as a defensive fortification against invasions from nomadic tribes, particularly from the north. It is not just a wall but a complex series of structures, including watchtowers, garrison stations, and fortresses. The Great Wall stands as a testament to ancient Chinese engineering and military strategy, symbolizing the strength and determination of the Chinese people throughout history.