2. There are 15 strategic passes from the East to the West
The Great Wall stretches across 15 northern Chinese provinces, municipalities and autonomous regions, from the Bohai Sea in the east to the Gobi Desert, 2,500 kilometers away in the west. There are 15 geographically important passes built along the route.
3. It took over 2,000 years to construct the wall
The first emperor of China, Qin Shi Huang took the remnants of ancient fortifications, walls, and earthworks and linked them into a unified wall circa 220 B.C.
This picture shows the "First Pier of the Great Wall" which was built with rammed loess in 1539 A.D.
4. It is not a wall but a series of fortifications
The Great Wall is not a single-structured wall, it includes beacon towers, barriers, barracks, garrison stations, and fortresses along the walls, together forming an integrated defense system.
5. Various materials were used to build the Great Wall
The Great Wall is a massive monument built with different materials. Most of the sections we see today were built with bricks and cut stone blocks, and lime mortar was used to hold the bricks together.
Where bricks and blocks weren't available, tamped earth, uncut stones, and wood were used as local materials.
6. The eastern beginning in the sea: Shanhai Pass
Shanhai Pass was a fortress built in the Ming Dynasty (1368 – 1644) and is the first pass in the East of China. It is located outside of Qinhuangdao City on Bohai Bay and 305 km away from Beijing. Given its strategic location, it's reputed as the "First pass under heaven".
8. An ancient tale of love: the legend of lady Mengjiang
It's one of the four greatest love legends in ancient China. Lady Mengjiang's husband was sent to build the Great Wall, and never gave news. She departed to bring winter clothes to him but heard that he had already died. She weeped so bitterly that part of the wall collapsed.
9. The workers from ancient times left marks on the bricks
Some say that the texts on the bricks is a method that General Qi Jiguang devised in order to assess the quality of the bricks made by the soldiers, and to clarify the responsibilities. However, historians questioned this. Read more here
10. It is Chinese people's greatest cultural icon
The Great Wall is the product of countless labors over a period of 2,000 years, and is a feast of engineering. It also reflected the collision and exchanges between the agricultural and nomadic civilizations.
In the Yuan Dynasty (1272-1368), the Juyong Pass functioned as a major traffic artery from Beijing to Inner Mongolia. Since Yuan emperors often took this route between those places, temporary imperial palaces, temples, and gardens were constructed.