WHAT WAS THE LOCATION OF THE GREAT WALL OF CHINA BUILT ON I NEED TO KNOW NOW IM DOING A REPORT THAT

Most of the sections were built in northern part of China including Ningxia the Ningxia Hui Autonomous Region, Gansu Province, Shanxi Province, Shaanxi Province, Hebei Province, Beijing, Tianjin, Liaoning Province. Presently, only the sections in Beijing and Tianjin are best protected. Sections in other provinces cannot be found or only the ruins left.
These are all I know.