Introduction to the three-layered tombs: The three-layered tombs are a group of three tombs with an overlapping relationship. The tombs are numbered M126, M137, and M140 from top to bottom. This phenomenon reflects the repeated use of the cemetery over a long period of time. Among them, the owner of tomb No. 137 is a young woman about 25 years old. Anthropology experts have conducted detailed measurements and studies on her skull. They found that there is a bone suture running through the zygomatic bone in the middle and lower part of the left zygomatic bone. This suture connects the zygomatic bone. The bone is divided into upper and lower parts. Since this feature is common among Japanese, the cheekbone block below is called the "Japanese bone". It is also one of the four "best in China" at the Tanshishan Cultural Site.