The Great Wall of China is one of the most iconic landmarks in the world, spanning over 13,000 miles across China's northern borders. The wall was built over several centuries, beginning in the 7th century BC and continuing through the Ming dynasty (1368-1644 AD).
The earliest sections of the wall were built by various Chinese states to protect against invasions from neighboring tribes. These early walls were made of tamped earth and were not very effective. It wasn't until the Qin dynasty (221-206 BC) that a unified China began building a more substantial wall made of stone, brick, and tamped earth.
During the Han dynasty (206 BC-220 AD), the wall was extended to the western regions of China to protect against the Xiongnu, a nomadic tribe from the north. The wall was further extended during the Northern Wei dynasty (386-534 AD) to protect against the Rouran, another nomadic tribe.
In the 14th century, during the Ming dynasty, the wall was rebuilt and extended to its current length. The Ming dynasty used bricks and stone to construct the wall, which was then reinforced with watchtowers, barracks, and fortresses. The wall was also widened to allow for the movement of troops and supplies.
Despite its impressive size and construction, the Great Wall was not always effective in keeping out invaders. The wall was breached several times throughout history, including by the Mongols in the 13th century and the Manchus in the 17th century.
Today, the Great Wall of China is a popular tourist attraction and a symbol of Chinese history and culture. It is also recognized as a UNESCO World Heritage Site.