The tomb is thought to have been built at some time between the end of the 7th century and the beginning of the 8th century.
It is said that the tumulus suffered from grave thieves around the Kamakura period; the southern wall of the stone chamber had an opening caused by grave thieves.
However the richly colors of the mural paintings kept almost intact and part of burial goods escaped grave robbing were discovered.
But, at the museum to which we went displayed only a replica of the the mural paintings.
The real mural paintings were stored in a conservation facility to avoid further deterioration.