QUOTE
In 1033, Koryo undertook a massive construction program to build a great defensive wall across its northern frontier to block not only the Khitan, but the Jurchen of eastern Manchuria as well. After eleven years of intensive labor, the massive rampart, modeled after China's northern defense line, linked fourteen walled towns in a line that stretched northward from the mouth of the Yalu River, through the mountains near the headwaters of the Chongchon and Taedong Rivers, to the east coast near Toryonp'o, the modern port of Yonp'o.

If there are any photos of the parts of the Great Wall that are still intact, I cannot find them.
