The Great Wall is a series of stone and earthen fortifications in China, built from the 5th century BC to the 16th century AD. It was constructed to protect the Chinese Empire from raids by various nomadic groups in the north. The Great Wall stretches over 21,000 miles (35,000 km) across the country, with sections built during different eras and by different dynasties. Its history and iconic status have made it a popular tourist destination and a symbol of China\'s ancient culture and history.