If you owned a certain piece of territory and wanted to prevent outsiders from entering, wouldn't you think of building a wall around it? In ancient times in China, such walls were built around entire cities to protect them from invasion!

       About the year 221 B.C., a great Emperor united different parts of China into an empire. His name was shih Huang Ti. But north of his empire there lived barbaric wanderers of the desert lands and he felt they were a danger to his new empire. So he ordered that a wall be built so long and so high that all the northern provinces of China would be protected.

     This Great Wall, which was truly a tremendous project, was completed in only 15 years. Since that time, it has been extended, rebuilt many times, and destroyed in part. But despite that, much of it still stands.

      Did the Emperor accomplish his goal with the Great Wall'? Unfortunately,  no. It simply wasn't too good a way of preventing the barbarians from invading China. Besides, there were always some parts of the Wall that were in need of repair. So the barbarians,   who were called Mongols, wandered back and forth across these broken-down parts. Not only that,   but the Chinese themselves didn't even stay within the Wall. Sometimes Chinese farmers would plant crops beyond the Wall.

     Despite this, the Great Wall did serve, and still serves today, as a kind of boundary between Chinese, and Mongol culture, and between a way of life based on agriculture and one of nomadic (wandering) herding.

    The Great Wall is the longest wall in the world. With all its windings, it is more than 1,500 miles long. Because it was built as a defense system,  it follows mountain crests and takes advantage of narrow gorges.

    The Wall is built of earth, stone, and brick. Its height ranges from 15 to 30 feet, with watchtowers rising at regular intervals above it. Along the top runs a 13-foot-wide roadway.