The Great Wall of China, as most of us know, is one of the largest engineering and building projects ever carried out in the world. It was originally built as a defensive system against invasion and attacks, but is now one of the biggest tourist attractions.
Structurally, the wall is made up of numerous walls constructed over two millennia, across northern China and southern Mongolia.
History goes that in the 7th century BC the state of Chu began to construct a permanent defensive system which was called the Square Wall. Between the 6th and the 4th centuries, other states too followed the trend. Later in the 3rd century BC, Emperor Shihuangdi of the Qin dynasty connected a number of walls into a single system.
The most extensive part of the Wall runs for 8850 kilometres, from Mount Hu to Jiayu Pass. The wall, with all of its branches measure out to be 21,196 kilometres!
