Great Wall of China
The Great Wall of China (长城 Chángchéng) stretches from Liaoning Province through Hebei Province, Tianjin Municipality, Beijing Municipality, Inner Mongolia Autonomous Region, Shanxi Province, Shaanxi Province, and Ningxia Autonomous Region to Gansu Province within the country of China.
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 access from 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.
The Great Wall, as we know it, is actually a series of several walls built at different times by different emperors.
First Great Wall
The First Great Wall was ordered built in 214 BC by Qin Shih Huang Ti 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, Taizong, was quick to see the benefits of the wall against the raiders and ordered more wall to stretch out as far as Zhaoxiang, Gansu Province.
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 Province and Lopnor and other outposts in Xinjiang Province. 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.
The geography of Northern China ranges from mountainous in northeast Liaoning and Hebei Provinces, through the grasslands of Ningxia, semi-arid desert of China's loess plateau, and borders the sand dunes of the Tengger desert of Inner Mongolia. It is the area around Hebei and Beijing that most people associate with the Great Wall, but most of the Great Wall lies in the desert regions of the country.
Flora and fauna
Chinese wildlife is diverse, considering all of the different habitats available along the length of the Great Wall. From the rare Siberian tiger in the northeast to the protected and rare Giant Panda which lives in southern Gansu, Sichuan, and Shaanxi, you never know what you might see on a given day.
Wild mammals can be found in the north, such as the Manchurian weasel, brown and black bears, northern pika, and mandarin vole. Deer species include Sitka deer, roe deer and the long-sought-after spotted deer, which has many uses in Chinese medicine.
The birds of the region include various pheasants, black grouse, pine grosbeak, various woodpeckers, mandarin duck, and the fairy pitta, a rare migratory bird. Cranes are especially revered in China. Common, demoiselle, white-napes, hooded, and red-crowned cranes all breed in China.
You can find many tonic plants along the Great Wall, such as the rare ginseng (Panax ginseng). Chinese medicine has had many thousands of years to discover and use these tonic plants for the benefit of mankind.
Northern China has all four seasons and they arrive with a vengeance. Summer and winter temperatures normally reach extremes of over 40 degrees Celsius and -20 degrees Celsius respectively.
As the Great Wall of China is rather on the long side, there are a large number of places to visit it. The following list is divided by province/municipality.
The most popular sites can be visited in one day starting from Beijing.
Note: There are many different 919 buses. The one to Badaling is at the very rear (farthest east) of the station. Be very wary of men in blue jackets posing as transit workers. They will lie all the way up to the bus door (and in front of real transit workers) by saying there are no more buses, it is the wrong bus, or that they are overpriced, etc. and try to get unknowing passengers to take their overpriced taxi and/or shuttle. The real transit workers around the area will be of no help (as they may be taking a cut), so you must ask the ticket giver directly on the bus if it is the correct bus. It will be only 12RMB.
You can also take a 919 home for 12 RMB, which means that you can stay as long as you like. Alternatively, take the train from Beijing North Station (14 RMB one way for hard seat, which is still nicer than most airplanes, with plenty of leg room). But make sure to call ahead or check online for the times as they change often.
For those that like to travel by train, a relatively underused way of travelling to the Badaling great wall is via a train from Beijing North Station. The schedule posted on seat61 seems to be pretty safe. This allows you time to visit the wall at your own leisure, bypassing the need to go to the Ming Tombs and random stores. The train has very large viewing windows, allowing you breathtaking views of the scenery and the great wall even before you arrive at Badaling. Tickets costs 6 each way, they must be purchased the same day of travel but only after 10AM, and only from the Beijing North Station. There is no time on the ticket so you may use the ticket for any train that day. If you don't want to wait in lines to buy tickets you may also use your subway card to board and pay for the trip. If you can't find empty seats you can hang out in the nearly empty dining car, which has a couple of comfortable booths with tables. Upon arrival at Badaling station you'll need to make a left turn and walk 800m to the great wall entrance. Badaling entrance fee is ¥45. Audio tour service 15/40y for chinese/english + 200y deposit.
The hike is still a challenge with plenty of steep hills, so once you get a bit into the wall the crowd thins quickly. On weekdays, there aren't any vendors chasing you on the wall; they stay in the little town area. In addition, there are Sun Bears that you can feed carrots to for 3 RMB in the little town. Don't take the 100 RMB tours that people offer you outside the Forbidden City or at Tiananmen Square - you only get 2 hours at the wall, and then you go to the Ming Tombs (read: big hill) and have to eat lunch; in addition, they can cancel the bus on you, they don't leave until the bus is full, and you have to stay with your tour group (with the loud mega phone and all) in order to get back to the city. Full walk path is: tower/path closed <> Guizhou pavilion for the stele <> (cable car/?closed) <> tower <> path to exit / great wall museum <> (sliding car, ?stairs) <> 6th tower <> 8th tower (top; cable car nearby ~100m) <> tower <> 10th tower in the north (stairs) <> tower/path closed. Cable/sliding car costs ~¥30/60 one/both way and it takes ~2-3h to do the whole wall depending on your fitness/weather/crowd.
The actual bus stop Huairou Beije is not a bus terminal or anything with a 'Great Wall' on it - just a normal street bus stop. When you get off the bus you need to cross the road as your going in the opposite direction. (you will see a large roundabout your going straight through this). The hawking is unbearable and extreme so be prepared. We waited at the bus stop for 45 mins on a Saturday (which is not sign posted with the correct number for the wall either. Finally we gave in and haggled a mini bus down to 5RMB each (3 of us). We got the 867 back to Beijing which takes 2hrs 45mins but is not stressful. This is coordinates on google maps of where the bus will drop you off - 40.33492,116.628322.
Prices vary around ¥30 per person for a return trip with waiting 2h, plus ¥5 for the parking when going out. For the return journey, the 867 leaves at 2.00pm and 4.00pm from parking lot 3 - the same place it dropped you off at Mutianyu if you caught it in the morning. Note that on Sunday 4:00 PM bus might be really crowded. It is an official looking bus with a number on it so don't be fooled by any other drivers (e.g. minibuses) who try and steal your business. Also, do not be fooled by any taxi drivers who say "no bus!". Mutianyu is magnificent. New entrance fee is ¥45, ¥25 for students only with ID containing a photo. Besides that, the cable car to the wall costs more than the wall entrance: ¥65 for adults and ¥45 for children, alternatively the 15 min. walk uphill through the beautiful park and forest is free. If you're not afraid of walking through some shrubbery, and you've got some grip on your shoes, continue on past the restored section and head to the highest local watchtower. You will be greatly rewarded for your effort!
The last buses to Beijing Dongzhimen from Huairou city are the 936 at 17:00 while the service of the 916 ends at 19:00. Without the Beijing transportation card (that you can purchase at any metro station) the price is 16RMB but with the electronic card excpect to pay less than 5RMB. See the details about the card on in the Beijing "Get around" section.
If you miss the bus, there is accomodation to be found near the shops in Huairou. There is a tourist information office that remains open during normal office hours, though it may seem closed due to lack of visitors. They will be able to help you find accomodation that is licensed to take foreigners, should you need it. The nearby "Yanxi Nightless Valley" area is full of small forest resorts, where you can pay around 100 RMB for a fresh, farmed trout. Stay in the valley the night before, then hire a taxi out direct to one of the nearby Great Wall sections in the morning.
Simatai is closed but you can still sleep on its section and do the trek from Simatai to Jinshanling.
Bring a jacket against the wind or cold in the chillier seasons. In summer you will need lots of water, but there are plenty of vendors at the most visited sections. Be prepared for the possibility of sudden, short, but rather violent thunderstorms.
Do not leave any trace of your visit. Even if it is not an uncommon sight, resist the urge to add your name to the carvings in the wall, or take a piece home as a souvenir. If the wall should be damaged by your actions, the authorities may very well take action with fines and other punishments.
Hiking as a recreational sport is not well understood yet in China so the etiquette of crossing state and private land has not yet been established. Remember that the Wall is mostly mud and poorly supported stones, and that you are on your own if you're outside the maintained areas. Even if you are not walking on the wall, you will find few trails to follow and at some parts, the area the Wall traverses are vertical, treacherous and very unsafe. Besides that, it is difficult to obtain clean drinking water and some areas may even have no water at all. Other areas will have manmade obstacles, like roads and motorways that have solid fencing. Villages where you could get supplies may be few and far between. Some may take you miles away from the Wall. Poor cartography is still a problem here since maps of less than 1:450,000 are not easy to get a hold of due to the military applications of such maps. Besides that, guides who know the areas along the Great Wall are few and far between. The last item to think about regarding hiking the Great Wall is that China has no system of mountain/wilderness rescue personnel. You will be on your own should something happen to you.
Scams - Beware of bus scams that may ruin your day. Also try to avoid organized tours to the Great Wall costing 100-150 Yuan. These are advertised by people handing out flyers around the Forbidden City in Beijing  for example (the real bus service to the Great Wall only costs 20 Yuan!). Also, the driver might just stop and set you off before your destination.
Badaling: Take bus 919 back to Beijing (12 RMB) or the train from either the Badaling or Qinglong Qiao stations (14 RMB). The last bus 919 leaves at 5 PM.
For other sections, hopefully you've come with a tour that is picking you up from that section. Taxis back to Beijing can be quite expensive (even from Badaling, it will probably be over 100 RMB).