Great Wall

Great Wall is a series of fortifications built along an east-west line across northern border with China.

After SG-1 had traveled to 1969 by Stargate then said Dr. Daniel Jackson if they could use the Stargate to travel in time so they could travel to China when the Great Wall was built.

A copy of the Great Wall of China is also aunnamed planet. Gus Bonner told the original wall was built to keep the Mongols out. A copy of the wall was a advanced alien race who had visited the Earth and built it in their museum.