The Great Wall of China was listed in the World Heritage by UNESCO in 1987 as one of the greatest wonders of the world. The most famous wall was built between 220–200 BC by the first Emperor of China, Qin Shi Huang. Its purpose is/was to protect the northern borders of the Chinese Empire. Several walls were built since the 5th century BC. It is a series of stone and earthen fortifications that has been, built, rebuilt, and maintained from the 6th century BC and the 16th century. The Great Wall stretches approximately 6,400 km (4,000 miles). It starts from Shanhaiguan in the east to Lop Nur in the west. It runs along the southern edge of Inner Mongolia and stretches to over 6,700 km (4,160 miles) in total. The Ming Wall was guarded by more than one million men.
To see the Great Wall in its most natural state visit Simatai, 110km (70miles) north-east of Beijing. This part is still in its original state without being developed into a popular tourist attraction.