China Wall

In 221 BC, the Emperor Qin absorbed the other six states and set up the
first unified kingdom in Chinese history. In order to strengthen his newly
born authority and defend the Huns in the north, he ordered connecting the
walls once built by the other states as well as adding some sections of
his own. Thus was formed the long Qin's Great Wall which started from the
east of today's Liaoning Province and ended at Lintao, Gansu Province.

In the beginning the wall was made mostly from dirt and other raw
materials. The workers would compress huge piles of soil, leaves, hay, and
mud into a wall. Not too long after starting, the Chinese changed from an
earthen wall only to a wall that was coated by stones, bricks, and granite
blocks, making a neat, sturdy long-lasting wall. During the Ming Dynasty,
watch-towers were turned into elaborate structures with tile patterns
circling the doorways. Altogether, one hundred and eighty million cubic
meters of packed earth and sixty million cubic meters of bricks were used
in constructing the wall. The amount of earth, stone, and brickwork in its
construction is more than enough to build a wall one meter thick and five
meters high around the equator.

I think that the amount of time and effort put into the building of the
great wall proves that the emperor was seen as a great power. The entire
country came together under Qin and as a whole the wall was built which
signifies not only the strength of the emperor but the country and it’s
people. A structure this significant takes serious amounts of labor and
many hands to complete it. People’s lives were one of the many costs at
the walls expense. Still standing today, this ancient architectural
structure signifies strength for China even after thousands of years have
come and gone.

http://www.history.com/videos/engineering-an-empire-china---the-great-wall#history-of-the-great-wall