Great Wall of China
Various dynasties · Beijing, China · 1644
The Great Wall of China is a series of fortifications built across the historical northern borders of ancient Chinese states and Imperial China. Its primary purpose was to protect against nomadic incursions, particularly from the steppes of Eurasia. Construction began as early as the 7th century BCE, with significant expansion and consolidation occurring under the Qin Dynasty (220–206 BCE) and most notably during the Ming Dynasty (1368–1644). The wall is not a continuous structure but a collection of distinct sections, often utilizing natural barriers like mountains. Materials vary by region and era, including rammed earth, stone, wood, and brick. Notable features include watchtowers, barracks, garrisons, and signaling systems. Its vast scale and continuous construction over centuries reflect a profound historical and strategic significance in Chinese history.