1. Great Wall of China
Emperor Qin Shi Huang, also called the First Emperor, who united China ordered the construction of the Great Wall around 221 B.C., the labor force that built the wall was made up largely of soldiers and convicts. It is said that as many as 400,000 people died during the wall's construction; many of these workers were buried within the wall itself.

The wall stretched from the China Sea port of Shanhaiguan over 3,000 miles west into Gansu province. The wall is widely thought to be about 5,500 miles (8,850 km) long and the work is supposed to began in the 7th century BCE and continued for two millennia (1878- Qing dynasty). Although it was built to prevent invasions and raids, the wall largely failed to provide actual security. Instead, scholars have noted that it served more as “political propaganda.”
In 1987, UNESCO designated the Great Wall a World Heritage site, 

Tidbit- William Edgar Geil, an American traveler, is the first person who has ever walked the entire Great Wall.
What do you find interesting in this? Have you visited the site or planning to visit?

This thread will continue with the other 6 wonders!