|Specified type||Prefecture designation|
|Designated date||April 1, 2005|
|location||Shimoharui County Yamadacho Hachimancho|
Yamada-cho's swamp? It is a group of documents excavated by excavation survey of the ruins.
Excavation was carried out from 1996 to 1997.
Investigation of the hill area was carried out triggered by the fact that the sword was found in the alluvial area that spreads under the hill in the survey of fiscal 1996, and it is one of the largest in Iwate Prefecture, and a well-preserved tomb group has been discovered .
The designated data group is the Tumon Sawa Ancient Tomb Group or related data group, including the Sword that triggered the discovery of the Tomb Group.