Under a flashlight the enigmatic beauty of the Fahai frescoes appears in its full glory. When the beam of light is thrown parallel to the frescoes (center), embossed parts of stucco and gold in the artwork are revealed.[Photo by Feng Yongbin/China Daily]

The alarming message was soon passed to Ye Qianyu (1907-1995), a renowned painter and art educator who at the time taught at the Central Academy of Fine Arts in Beijing. It did not take long before it reached other important cultural figures, and ultimately, the Beijing municipal government, which alerted the army.

"Any further damage by unmindful soldiers was stopped," Tao says. "Fearing that pulling out the nails might cause more destruction to the wall, they were allowed to stay."

They are still there on a lower section of the northern wall in the main hall, together with a couple of holes that used to hold the nails.

"As jarring as they may seem, these holes made possible the study of the wall's composition," says Tao, who attributes the survival of the murals to the walls' stability and to fate.

"Many Western murals painted around the same time suffered serious cracking and bulging, but this has rarely happened to the Fahai frescoes."