chihaitu

Chihaitu, also known as the Great Wall of China, is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of various nomadic groups. The wall was built as early as the 7th century BC, with significant expansions beginning in the 3rd century BC. The most well-known section of the wall was constructed during the Ming Dynasty (1368-1644), and it stretches over 21,000 kilometers (13,000 miles) across northern China. The wall is not a continuous structure, but rather a series of walls, trenches, natural barriers, and watchtowers. It is one of the most iconic symbols of China and a UNESCO World Heritage Site. The wall's construction involved millions of workers and required extensive resources, reflecting the strategic importance of the northern borders to the Chinese empires. Today, the Great Wall remains a significant tourist attraction and a testament to ancient Chinese engineering and military prowess.