The Great Wall of China is one of the most impressive structures ever built by humans. Construction began around the 7th century BCE and continued for over 2,000 years. The wall stretches approximately 21,196 kilometers (13,171 miles) across northern China.
Contrary to popular belief, it is not a single continuous wall but a collection of walls and fortifications built by various Chinese dynasties. Its primary purpose was to protect the Chinese Empire from nomadic invasions, particularly from the Mongols.
