The second important reason is that this painting has a high collection value. The Tang Dynasty was the heyday of the ancient feudal dynasty in China. During this period, a number of outstanding artists and calligraphers emerged. The artistic level of these artists can be said to run through ancient and modern times. In this era when ancient art is dying out, if the portrait of Wu Zetian can be found and studied, then traditional culture can be revived.
The third important reason is that Ganling not only has this treasure, but also has many antiques worth studying. Ganling is said to be one of the few tombs that have not been stolen by grave robbers so far, so the study of antiquities is very valuable. Not only that, the books collected by Gan Ling are also worth studying.
Another important reason is that there are many books recording history in Ganling. Through these books, we can restore the real situation of the Tang Dynasty more clearly, and these books can provide first-hand information for us to study the history of the Tang Dynasty. Therefore, many people would suggest digging a dry tomb, not only for portraits, but also for other things in the tomb.
Based on the above reasons, we can find that so many people want to open Ganling because of its high research value, but the current technology does not support us to dig Ganling.