Great Wall of China Facts

Is the Great Wall Visible from Space?

Great Wall of China
Alain Le Garsmeur / Contributor / Getty Images

A few of these Great Wall of China facts will certainly surprise you. Much of the stuff we're taught in school about the Great Wall isn't entirely accurate. Go stand on the wall with your own two feet and see for yourself.

It's certainly the longest man-made object on earth, a top UNESCO World Heritage Site in Asia, and a requisite for any visit to mainland China. But unless you're blessed with better-than-an-eagle vision that can rival modern optics, believe the astronauts over textbooks: the Great Wall of China is not visible from space.

Is the Great Wall of China Visible from Orbit?

Under perfect conditions, maybe, but it's doubtful. Despite the long-running myth that the Great Wall of China is the only man-made structure visible from space, astronauts disagree. Astronauts have mistaken other features for the wall but so far weren't able to see the structure without help from technology.

While in low orbit, an astronaut did manage to grab a picture of the Great Wall, but pointing a powerful camera sensor at it and getting lucky doesn't technically mean that it was seen with the naked eye.

Although waterways and many man-made objects — including roads — are visible from a low orbit, NASA says that entire continents blend together when viewed with the naked eye from both the moon and space. The Great Wall was constructed using local materials of similar color to the surrounding terrain, making it indistinguishable.

Why Did People Think the Great Wall Was Visible From Space?

Back in 1754, way before space travel was a thing, an English clergyman wrote that the wall is so long that it must be visible from the moon. Sir Henry Norman, an English journalist, decided to make the same claim in 1895. Both were impressed by the wall, but neither knew very much about space.

For decades to follow, the idea that the Great Wall of China must be visible from space was propagated by writers. Eventually, the notion became common belief and wiggled its way into textbooks.

Is the Great Wall One Continuous Structure?

Absolutely not. The Great Wall is actually a discontinuous network of walls and segments with spurs and offshoots. The sections were built over centuries; some were only connected by simple berms and earthworks. Sometimes geological features were used to chip away at the insurmountable task of constructing such a landmark. In some places, all that remains are battlements and small towers; the bricks of the wall were carried away and repurposed long ago.

Keep in mind that the Great Wall isn't completely linear in shape; it has branches, trenches, fragments, and sometimes even redundancy.

Calling the structure "The Many Wall Segments of China" just wouldn't have the same ring to it!

How Long Is the Great Wall of China?

Because the Great Wall is made up of many segments, many of which have eroded or were destroyed, getting an accurate measurement is difficult. GPS, ground-penetrating radar technology, and satellite imagery have all been leveraged to determine just how long the wall really is. An additional 180 miles of the wall covered by sandstorms were not discovered until 2009!

An estimate for the "Ming Wall" — what we most often consider to be the Great Wall of China — is around 5,500 miles (8,851 kilometers) long. One survey put all of the pieces of the wall combined to total over 13,000 miles long.

An estimated 22 percent of the Ming Wall has disappeared.

Is the Great Wall One of the Seven Ancient Wonders of the World?

Despite the age and size, the Great Wall of China never made it onto the list of seven wonders. Perhaps that's a good thing: the only remaining ancient wonder that has not been destroyed is the Great Pyramid at Giza!

The Great Wall of China was added to the so-called "New Seven Wonders of the World" by winning a poll conducted online and by telephone in 2007.

Did the Great Wall Protect China?

Unfortunately, the hard labor and monumental effort didn't quite pay off. The Great Wall never managed to keep out invaders from the north. It only slowed them down a bit. In fact, Manchurian nomads regularly made raids over the wall for years. They eventually controlled parts of China for 250 years.

Despite ultimately failing strategically, the wall did serve as a highway system for moving troops and goods through tough terrain, and signal towers provided an important communication network. Although raiders could circumvent the wall, it did provide observation and served as an early warning system to alert others that trouble on horseback was coming.

The Great Wall of China was a minor annoyance in the way for invaders throughout China's history, but it did provide jobs and wealth redistribution — as well as an outlet for banishing prisoners to go work in labor camps.

How Old Is the Great Wall of China?

Construction of early parts of the wall began over 2,000 years ago, however, what we consider to be the Great Wall of China was built during the Ming Dynasty in the 14th century to keep out Mongol raiders.

Did the Enemies of China Destroy the Great Wall?

No. The greatest damage to sections of the Great Wall came from farmers who took away fertile soil to use for planting (much of the wall began as rammed earth). The shaped bricks and stones were salvaged from many sections of the wall and used to construct roads!

Villagers were encouraged to take materials from the wall during China's Cultural Revolution between 1966 and 1976.

Is it Possible to Hike Along the Great Wall?

Yes. Some adventurers have even walked or cycled the entire length of the wall. Much of the Great Wall is in ruins, however, tour companies offer opportunities to even sleep atop less popular stretches of the wall.

Many stretches of the wall are closed off permanently for restoration work or archaeological studies which will most likely never finish, if they ever began in the first place. The Chinese government has been criticized for preventing access to segments of the Great Wall, not out of concern for the landmark, but to funnel tourists to more popular sections of the wall where tacky souvenir stalls abound.

Is the Great Wall Busy?

Make no mistake and don't believe what you see in photos: If you visit any stretch of the Great Wall within striking distance of Beijing, particularly Badaling, you'll be in the company of hundreds — if not thousands — of other visitors. You may as well learn how to say hello!

The wall is incredibly busy during big holidays in China such as National Day and Chinese New Year.

Other Interesting Great Wall of China Facts

  • Mao Zedong once said: "He who has not climbed the Great Wall is not a true man."
  • Dried wolf dung was burned by sentries along the wall to send smoke signals about enemy movements that were then relayed back to leaders. Flags were also used to signal other towers within eyesight.
  • Sections of the Great Wall are purported to contain the remains of workers who perished on the project. Despite the great loss of life while building the wall, archaeologists have not uncovered human remains.
  • Sections of the wall contain bullet holes from the Second Sino-Japanese War (1937–1945).
  • The wheelbarrow is among China's many inventions over the centuries. It was used to move materials while building the Great Wall.
  • President Nixon's historic 1972 visit to China included a tour of the Great Wall at Badaling, a popular part of the wall around 50 miles north of Beijing.
  • More than 25,000 watchtowers have been constructed along the wall throughout history.
  • Being sent to work on the wall was an extremely dreaded sentence and was often punishment for corrupt officials and upper class criminals who fell out of favor of the court.