Omi Shinkanji-kofun Tumulus (a keyhole-shaped mound in Omi-kofun Tumuli Cluster in Gyoda City, Saita (小見真観寺古墳)

The Omi Shinkanji-kofun Tumulus is a large keyhole-shaped mound located in Omi-kofun Tumuli Cluster in Gyoda City, Saitama Prefecture.

Summary

The mound of the tomb is 112 meters in length, a keyhole-shaped mound ranking the fourth in size in Saitama Prefecture and commonly called 'Kannon Dake' (Mt. Goddess of Mercy).

The main axis points west northwest, and although the left-side mound and the tops of front and back are flattened, the right-side remainders are in good condition. The back circular part is 55 meters in diameter and 7.8 meters in height, and the front square part 48 meters in width and 7 meters in height.

It was named so because it is in a temple region of Shinkan-ji Temple of Chizan school, Shingonshu sect on Mt. Shiun.

Burial Facilities
The mound has two corridor-style stone chambers built by fitting together some chrolite schist monoliths near the back circular part and the hollow part.

In 1634 the stone chamber of the back circular part was discovered and it had a front room and a back room and was built in the early seventh century.

The front room: 5.42 meters in full length, 2.24 meters in width, and 2.03 meters in height

The back room: 2.62 meters in full length, 2.33 meters in width and 2.02 meters in height

In the chamber in the hollow part a back room alone exists, while a front room remains unclear.

The back room: 2.8 meters in full length, 1.76 meters in width and 1.12 meters in height

Excavation investigation in 1880 found some artifacts such as armors, swords, copper bowls, earthen vessels, which are now stored and exhibited in Tokyo National Museum. From the chronology of grave goods, there is a possibility that the stone chamber was built a little later in the middle of the seventh century.

Designation as a Historic Site

It is new tumulus for a keyhole-shaped mound and is thought to be a headperson-class tomb equal to Sakitama-kofun Tumuli Cluster. On March 30, 1931 it was designated as a national historic site.