Yilian Youmeng.
The word Yilianyoumeng means that this evening is separated from the past, which means that the past has passed and cherish the present, which is very suitable for tombstones.
In ancient China, there were no tombs but graves. They were only buried underground and there were no signs on the surface. Later, gradually there were graves with earth piled on the ground and tombstones. After a person passes away, if a tomb is to be erected, most of the time there must be a tombstone.