1. The longest wall of the Great Wall is approximately 2,145 miles. Additionally, about 1,770 miles branch from the sides, making it the longest man-made structure in the world by far.
2. The length of all Chinese defense walls built over the last 2,000 years is approximately 31,070 miles. To put this into perspective, it could circle the world two times!
3. The mortar used to bind the stones was made out of rice flour.
4. Though the Great Wall of China is not one of the Seven Wonders of the Ancient World, it is one of the Seven Wonders of the Medieval World.
5. Parts of the wall were surrounded by moats, which allowed for additional defense.
6. The Great Wall attracts around 50 million foreign visitors annually.
7. The earliest major walls were built between 260-210 B.C. by the Qin dynasty.
8. After the Qin dynasty were the Han, Sui, Jin, and Ming dynasties. Most of what we see today is from the Ming dynasty.
9. The most visited section of the wall is in Badaling, which is close to Beijing and was built during the Ming dynasty. In 1957, it was the first section to open to tourists.
10. The height of the Great Wall varies anywhere from just above ground level to 30 feet high.
11. Who built the Great Wall? Most of the wall was built by guards, peasants, unemployed citizens, disgraced noblemen, and prisoners. Being forced to work on the wall used to even be a punishment for convicted criminals.
12. Several temples were built along the wall for Guandi, the war god.
A view of the Great Wall in 1907.