Secrets of the Great Wall

Documentary explores the history of the Great Wall of China. At about 30 feet in height and 4000 miles in length, the Great Wall is one of the largest construction projects on the earth. Running from the northwestern arm of the Yellow Sea, to a point deep in central Asia, the Wall was originally intended to keep out invading nomads. The program uses recent archeological digs and restoration projects to reveal secrets that have remained hidden for centuries. Using computer-animation and re-enactments, the program reveals how the Wall was built, how its defenses were designed and maintained and how it dominated both the landscape and culture of China for three millennia.
...from inbaseline.com