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 the various nomadic groups of the Eurasian Steppe. The Great Wall is the longest wall in the world, stretching over 13,000 miles.
Construction of the Great Wall began as early as the 7th century BC and continued through the Ming dynasty (1368-1644). The Great Wall is not a single continuous wall, but is made up of many walls and fortifications built by different Chinese dynasties over the centuries.
The Great Wall of China is an architectural wonder, it is also a symbol of Chinese civilization, and is considered one of the greatest engineering feats in history. The Great Wall is also a UNESCO World Heritage Site and one of the most popular tourist destinations in China.
The Great Wall is open to visitors all year round, but the best time to visit is from April to November when the weather is milder and there is less likelihood of rain. Visitors can hike along the wall or take cable cars or chairlifts to reach the top.