The Great Wall

Most students of history have heard of China’s Great Wall. Scholars seem to agree that this wall was constructed many centuries ago on an east-west orientation to protect China from neighboring invaders to its north. Much of the wall fell into ruin as the need for such protection subsided. In fact, one historian figured out that only 8.2 percent of it remains intact, while another 22 percent of it has completely vanished.

How Long Was It?

Did you know that nobody is sure how long the Great Wall really was? Until a few years ago, it was estimated to be 5,500 miles. Recently, however, archaeologists have proposed that its actual original length was closer to 13,170 miles. Not all of the structure was built by humans, as rivers, steep mountains, and other natural barriers were incorporated into the wall. Stretched out, it could run more than halfway around the globe!

How and When Was It Built?

The first sections of the Great Wall were constructed as long ago as the eighth century BCE, using mud and gravel that was packed together. With the invention of brick-making during the Tang Dynasty (618-907 CE), these sturdier, lighter components were preferred. One of the ingredients in holding the bricks to each other was sticky rice juice!

You may be interested to know that the barrier was not only a wall. The builders thought of every possible defensive need, so they included other elements:

• watchtowers
• drainage systems
• parapets
• ramps for horses
• armories
• barracks for soldiers

In the best-preserved, Mutianyu section of the wall, reinforced with granite in 1569, there are 23 watchtowers along 2,250 meters.

How Tall Was It?

The Mutianyu section’s average height is seven to eight meters in height, four to five meters in width. The top of the wall is narrower than the bottom. In some places, now, it has eroded to fewer than two meters.

Can It Be Seen From Space?

Despite the wall’s size and length, the popularly held belief that it can be seen from the moon is actually false. Scientists have estimated that it would need to be 70 miles wide to be viewed with the unaided eye from such a distance. Another comparison would be trying to see a human hair from two miles away. NASA has published photographs disproving this myth, so you can see (or rather, not see) for yourself.

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