First Emperor Qin was only emperor for 15 years. But in that time, he made great changes. It was under his rule that China became one country.
One of the things Emperor Qin wanted to accomplish was to strengthen China's protection from the Mongol tribe to the north. China's natural barriers in the east, south, and west, protected her from invasion. But China was vulnerable to the north.
Emperor Qin set people to work to build the Great Wall. Qin wanted a wall 30 feet wide and 50 feet high. This was quite an engineering feat!
Qin put many people to work building the wall including criminals, scholars, captured enemies and anyone he felt like assigning to the wall construction. Laborers who worked on the wall were not paid and they were not given very much food. It was slave labor and very harsh. People died of disease and exhaustion. There were accidents from falling rocks.
The Great Wall took a little longer than Qin had originally thought it would to build. It took over 1700 years! Emperor after emperor followed Qin's lead and forced people to build the wall. A great deal of the wall was built during the Ming Dynasty (1360-1640, during the Middle Ages and into the Renaissance.) By the time the wall was done, it was over 13,000 miles long!
Barracks were built on the Great Wall to house soldiers who stood guard to defend China from attack from the north. Wide moats were build outside the wall to make approach even more difficult. Watch towers and beacon towers were built to send smoke signals, a sign of danger. When the people saw smoke rising from the wall, they knew the enemy was approaching from the north. Other soldiers ran to assist the soldiers on wall to stop the enemy from entering China.
The ancient Greeks were so impressed with the Great Wall that they named it one of the seven wonders of the world, now referred to as one of the seven wonders of the ancient world! The truth is, the Great Wall did not work very well as a defensive barrier. There were too many open areas and the wall kept decaying. It is still decaying today. Over the years, roads have been cut through the wall. The government of China continually attempts to keep the wall from further damage. It is quite a job, as you can imagine!
A great deal of the Great Wall still stands. You can visit it. You can stand on it. You can walk for miles on it. You can even see it from space! It is the largest man made structure in the world. It attracts thousands of visitors every day.