New Mysteries In An Ancient Chinese Wall, Revealed

A new detection method has shined some light on the fortress walls of Xi’an, China. These thick structures are measured to be 12 meters high and up to 18 meters thick. They served as great defenses for the residents of the city, but they are also impervious to analysis and scanning. 
One type of subatomic particle was found to be able to bypass the thickness of the fortress walls. These particles, called muons, can now be used to assess the structural integrity of the walls so they can be preserved in more years to come. 
New muon scans of the walls revealed density fluctuations inside one of the sections of the walls. These fluctuations could be signs of two things: dangerous flaws that should be repaired or hidden structures. According to nuclear physicist Zhiyi Liu of Lanzhou University, the latter could be “archaeologically interesting for discovery and investigation.”
Read more about the fortress walls here!