Structure of Mutianyu Great Wall
Like other sections of the Great Wall, Mutianyu has a superstructure in the form of a rampart, or a protected parapet with crenellated walls that reach about 5 feet above the height of the parapet (a crenellated wall consists of solid sections (merlons) that alternate with gaps (crenelles) for firing a weapon). The usual crenelle is rectangular, while some of the crenelles of the Mutianyu section of the Great Wall are of a saw-toothed shape. Mutianyu Great Wall averages an own-height of 78 meters, with a width of some 45 meters.
Unlike many other sections of the Great Wall, most parts of the Mutianyu section are constructed of granite, making the wall here extremely robust, though the parapet and the crenellations are of brick. The towers of the Mutianyu section are not so much towers as squat, mini-fortresses dotted along the length of the wall. They are a sort of fortified, oblong (rectangular) building, about three times wider than the wall itself, with space inside for the storage of weapons and ammunition - as well as food and drink and some sleeping accomodations - and with an inner staircase that provides access to the parapet above and to the row of "windows", or embrasures, located one storey below the parapet, and whose openings are much wider on the inside than on the outside of the enormously thick walls, making them ideal for defensive purposes, since a defender can see the would-be attacker before the would-be attacker spots the defender (with embrasures, two defenders stand at either side of the wide inner opening, firing across each other's line of fire, though surely at different heights, or levels).
As an added measure of security, the Mutianyu section of the Great Wall is crenellated on the inner side as well as on the outer side, and same applies to the embrasures of the watchtowers. This meant that the wall's defenders could protect their rear guard in the event of a breach of the wall at any given point (the fact that the Mutianyu section of the Great Wall is so well-preserved suggests that would-be attackers chose to mount their attacks on less-impregnable sections of the Great Wall). Another function of the watchtower, as the name implies, was as a sentry post for observing approaching invaders. In this connection, an integral part of the watchtower was its signalling platform, which was used to light a fire of special material that would smoke profusely, as a way of warning adjacent watchtowers of the impending danger, and of summoning help (the more watchtowers that sent up smoke, the larger the attacking force).
Mutianyu Great Wall
The Gateway of the Mutianyu Pass is located about 2 kilometers northeast of Mutianyu Village. The gateway consists of 3 towers - one large and two small - though, in essence, this is one large fortress building whose center tower is wider and longer than the two side towers, though they are all three interconnected on multiple levels, and capped with small house-like structures with traditionally sloping, A-shaped, slightly swaying roofs whose non-upturned eaves only extend far enough beyond the "house's" walls to shed rainwater (which would thus fall inside the tower's widened rampart).
There is a dauntingly steep, 454-step, jackknifed staircase located at Mutianyu Pass, which may help to explain the existence of an adjacent cable car for those whose constitution is not up to such an arduous climb, though critics have slammed the cable car as a disfigurement of the Great Wall. In further defense of the cable car, the walk along the 22 kilometer wall is not just along the parapet itself, since there are many special features at certain sites where one descends a winding staircase in order to inspect the features properly, only to return to the parapet, and this can be gruelling enough, so the easy beginning seems, on balance, entirely justified, in spite of its aesthetic detractions.
Mutianyu Greatwall History
The current Mutianyu Great Wall is an improved version of the original, erected on the site of the older section of the Mutianyu Great Wall that was first constructed during the Northern Qi (CE 550-577) Dynasty of the Southern and Northern (CE 420-588) Dynasties period, thus making it older than the Badaling section of the Great Wall, which is located closer to Beijing (and note that the farther from Beijing, the less trafficked is the section of the Great Wall). The original Mutianyu Great Wall stood unchanged until 1404, the second year of the reign (CE 1402-1424) of the Yongle Emperor (aka Emperor Taizong), when a pass was made in the original wall at Mutianyu during the Ming (CE 1368-1644) Dynasty.
Almost two centuries later, in 1567, General Qi Jiguang, who had earlier served as the leading general in charge of suppressing the Japanese pirates (the so-called wokou) who were harassing China's northern coast (in this endeavor, General Qi also engaged the help of two other renowned generals, Generals Tan Lun and Yu Dayou, who are sometimes mistakenly credited for having reconstructed Mutianyu Great Wall), was summoned to the capital in order to train the Imperial Guards as part of the northern defense against marauding Mongol warlords who continued to plague the empire.
A year later, General Qi was put in charge of a large military contingent whose mission was to suppress the increasingly bothersome Mongol incursions. It was in this capacity that General Qi decided to reinforce the Great Wall along almost its entirety, from Shanhaiguan (Shanhai Pass), near the port city of Qinhuangdao in the Bay of Bohai, to Juyongguan (Juyong Pass), near Guangou Valley, situated some 50 kilometers northwest of Beijing. This immense construction project included extensive repairs and improvements to the Mutianyu section of the Great Wall, such that this section of the Great Wall can rightly be credited to the tactical genius of General Qi Jiguang (it is said that from the general's refortification of the Great Wall until his death 16 years later, not a single Mongol breached the improved defenses that the general had put in place).
In addition to the pass at the village of Mutianyu, the Mutianyu section of the Great Wall is famous for three other noteworthy sites, namely, the Ox Horn Edge subsection that stands over 1000 meters above sea level, and the Arrow Buckle and Flying Eagle Facing Upward subsections, both of which are erected on cliff faces which themselves are all but impregnable.
Any visitor to Mutianyu Great Wall should devote enough time to appreciate the pass at Mutianyu as well as the three other aforementioned noteworthy sites on this justly famous stretch of the Great Wall, which is considered the best-preserved - and perhaps best constructed - section of the Great Wall. Besides the impressive wall itself, this section of the Great Wall snakes through an incomparably beautiful woodland - covering about 90 percent of the mountains - that is intersected by numerous streams, thus adding a special dimension to the visitor's experience of this unique section of the Great Wall.