Describe two specific aspects about the great wall of china

Describe two specific aspects about the great wall of china

Describe two (2) specific aspects about the Great Wall of China, such as facts about its size, length, purposes, varied materials, labor force, and its phases of construction. Consider the various purposes of such a wall and its impact for good or bad, and compare the Chinese wall in this respect to some specific wall of more modern times.

Some extra information that may help.

Chapter 7 (pp. 216-218, 225), early phases, (pp. 617-618) later phase

Explore wall interactively at http://www.airpano.ru/files/China-Great-Wall/2-2

Video at http://www.discovery.com/tv-shows/other-shows/videos/discovery-atlas-china-revealed-the-great-wall.htm

UNESCO article at http://whc.unesco.org/en/list/438

“China’s Wall Less Great in View from Space” article at http://www.nasa.gov/vision/space/workinginspace/great_wall.html