A map in the tiny museum at Yang Guan provides an idea of how extensive the fortifications were in the area.  In addition to the watchtowers I have marked in red, and for which the original of the map has small photographs of the ruins, there are numerous other locations with archaeological remains of significance.  Clicking on the tower in the center of the map will bring up a view of its remains and the view from it across the highlands of the desert to the south.  The tower is located where there also had been a major fort, none of whose remains can be seen.

© 1999 Daniel C. Waugh