Great Wall of China
700 BCE – 1644 CE
The largest defensive structure ever built by human hands — a sprawling system of walls, forts, and watchtowers stretching over 21,000 kilometres across northern China, constructed and rebuilt across more than two millennia by successive dynasties from the Warring States period through the Ming. Far more than a single wall, it represents the accumulated military engineering of an entire civilization defending its northern frontier against nomadic incursion.
732
Iron AgeClassicalImperial China
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