Great Wall of China is a series of stones and bricks in the northern part of China
. It was originally built to protect the northern borders of the Chinese Empire against invasion from local nomadic communities. The wall has been rebuilt severally and maintained since the 5th Century up to date. Several walls have also been rebuilt and called the same name. The most famous one was built in 220- 206 BC by the first Emperor of China, Qin Shi Huang. Great Wall of China inclusive of its branches stretches for 8,851.8 km. The walls have 359.7 km of trenches and 2,232.5 km of natural barriers such as rivers and hills. The area is well conserved and open to tourists. Some of the notable areas include West Pass of Jiavuguan. This is a fort on the western edge of the wall. There is North Pass of Juyongguan known as Badaling. The area was used by the Chinese to protect their land and was guarded by the military. The section of the wall here is 7.8 metres high and five metres wide. Great Wall of China has a notable are feature referred to as Shanhaiguan. This is where the first pass of the Great Wall was built. It's also kwon as Number One Pass Under Heaven' and lies on the first mountain the wall climbed. Another area around here is Jia Shan and it's the only portion of the wall that that was built as a bridge. Before the wall was rebuilt with stones and bricks it was mainly made of rammed earth, stones and wood. It's during the time of the Ming Dynasty that it was reconstructed.