[[File:The Great Wall of China at Jinshanling.jpg|thumb|250px|The Great Wall of China at Jinshanling]]
The Great Wall of [[China]] can be visited at many places along its length of several thousand kilometers. Its condition ranges from excellent to ruined, and ease of accessibility varies straightforward to quite difficult. Note that different sections also each have their own admission fees, e.g. if you want to hike from Jinshaling to Simatai then you probably have to pay twice.
[[Image:Picture 144.jpg|thumb|250px|Great Wall of China at Badaling]]
'''The Great Wall,''' as we know it, is actually a series of several walls built at different times by different emperors. The categories below are non-exhaustive, and all refer to wall systems rather than single monolithic walls.
* '''First Great wall''' - built by the Qin Dynasty 221-207 BC
* '''Second Great Wall''' - built by the Han Dynasty 205-127 BC
* '''Third Great Wall''' - built by the Jin Dynasty 1200 AD
* '''Fourth Great Wall''' - built by the Ming Dynasty 1367-1644
====First Great Wall====
'''First Great Wall''' was ordered built in 214 BC by Qin Shih Huangti after he had finished consolidating his rule and creating a unified China for the first time. The wall was designed to stop raids by the Xiongnu raiders from the north. 500,000 laborers were used during the 32-year building period to create the First Great Wall.
Although the wall worked at keeping out enemies, it did nothing to stop internal pressures which lead to a regime change in 206 BC and the new leadership of the Han Dynasty. The first Han emperor, Gaozu, was quick to see the benefits of the wall against the raiders and ordered more wall to stretch out as far as Zhaoxiang, [[Gansu]].
====Second Great Wall====
Over 70 years later, the Han Dynasty were still fighting the raiders since the Great Wall had been left to deteriorate and the raiders had breached it in several places. In 130 BC, Emperor Wudi of the Han Dynasty embarked on a program of extending, rebuilding and fortifying the original First Great Wall. After the emperor finished adding more regions under his rule in 127 BC, he ordered a major expansion program that created the '''Second Great Wall''', outposts in [[Zhangye]], [[Wuwei]], [[Jiuquan]], [[Dunhuang]] and Yumenguan in [[Gansu]] and Lopnor and other outposts in [[Xinjiang]]. The Great Wall was extended down the Hexi Corridor through which the [[Silk Road]] traders would travel on the way to and from the West.
When the Han Dynasty fell apart into the three kingdoms of the Wei, Shu and Wu, the northern Wei kingdom decided to continue maintaining the Great Wall so that they could keep out the Rouran and Qidan nomads from the northern plains. Despite the constant maintenance, the Wall kept being breached by the Rouran nomads. Additional walls were built inside and outside of the Great Wall by the different kingdoms. Eventually the Wei kingdom merged with the unifying Sui kingdom and was overthrown by the Tang Dynasty in 618 AD.
Nothing more was done to the Great Wall until the reign of the Liao and Song dynasties. The Liao Dynasty controlled the north while the Song Dynasty controlled the south. The Liao were troubled mainly by a tribe in the northeast region of China called the Nuzhen (known as Manchu in Mandarin) so they built defensive walls along the Heilong and Songhua rivers. These failed to stop the raiders from coming south.
====Third Great Wall====
In 1115, the Nuzhen established the Jin Dynasty and since they were from the north themselves, understood that the Mongols were right behind them. The Jin emperor ordered the construction of a '''Third Great Wall''' to be built in [[Heilongjiang]] Province and [[Inner Mongolia]] Autonomous Region. The walls built had the characteristics of having ditches running along the walls full length.
Despite the impressive fortifications built, the Mongols overthrew the Jin in 1276 and established the Yuan Dynasty. During the Yuan dynasties rule, the Wall fell into deep disrepair and in 1368, the Chinese Ming Dynasty walked right in and took control.
The Ming Dynasty, after getting rid of the Mongols, determined that they would never be taken again by outsiders. The first emperor of the Ming Dynasty, Hongwu, re-established manning of the Great Wall, fortresses and garrisons were built along the wall, and the fort at [[Jiayuguan]] was built in 1372 at the western end of the wall. The second Ming emperor, Yongle, turned his focus outward from the empire and sent out explorers and diplomats into the big, wide world.
====Fourth Great Wall====
It was not until the battle of Tumu against the Mongols that renewed interest in reinforcing the Great Wall occurred. Between 1569 and 1583, the most well-known parts of the Great Wall were built, the '''Fourth Great Wall'''. The reinforced wall managed to repel Mongols several times.
The Manchu retook China in 1644 and formed the Qing Dynasty. From this point on, the Wall slowly started to fade away while stone and rocks were taken from the Wall for building projects and homes. The Cultural Revolution definitely took its toll out on the wall when local people and local governments were encouraged to help dismantle the Great Wall.
It was not until 1984 that President Deng Xiaoping started a restoration and protection project of the Great Wall. In 1987, the Great Wall was declared a World Cultural Heritage Site by UNESCO.