An amazing feat dating back to the 5th century and spanning many centuries to build, The Great Wall is 13,170 miles long, making it the longest structure in the world. Initially built as a defense against enemies, the Great Wall of China stands today as a major tourist attraction for visitors worldwide. It has been a UNESCO World Heritage Site since 1987. The main Great Wall line stretches from Shanhaiguan in the East, to Lop Lake in the West, along an arc that roughly delineates the southern edge of Inner Mongolia.
The Great Wall of China is a series of military fortresses made of stone, brick, earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire. The Great Wall has on and off been rebuilt, maintained, and enhanced, the majority of the existing wall are from the Ming Dynasty. While some portions north of Beijing and near tourist centers have been preserved and even extensively renovated, in many locations the Wall is in disrepair. Those parts might serve as a village playground, or a source of stones to rebuild houses and roads.