The Great Wall of China is one of the most notorious structures in the entire world. The Jinshanling section in Hebei Province, China, pictured here, is only a small part of the wall that stretches over 4,000 kilometers (2,500 miles).
The Great Wall of China was originally built during the Qin Dynasty (221-206 BC) by Emperor Qin Shi Huang to protect the newly founded empire from invasions by nomads The wall was initially built of rammed earth and later extended and fortified by successive Chinese dynasties, including the Han, Sui, and Ming Dynasties .
Did you know? When Emperor Qin Shi Huang ordered construction of the Great Wall around 221 B.C., the labor force that built the wall was made up largely of soldiers and convicts. It is said that as many as 400,000 people died during the wall's construction; many of these workers were buried within the wall itself.