Hanishina Kofun group

The Mori-Shōgunzuka Kofun is located in what is now part of Chikuma city. It is the largest keyhole-shaped kofun in Nagano Prefecture with a total length of over 100 meters. However, it is not bilaterally symmetrical due to being built on a curved ridge with a height of 130-140 meters, and the rear circle is nearly elliptical. The mound was once covered fukiishi stones, and once had many cylindrical haniwa. The anterior portion has a length of 40 meters and width of approximately 30 meters, with a height of 4 meters. The rear circle has a diameter of 45 meters and height of 4 meters. From the style, it was constructed at the end of the fourth century, and is assumed to be the tomb of a local king prior to the establishment of Shinano Province.

The mound contains a burial chamber a double stone walled burial chamber, 7.6 meters wide, with a height of 2.3 meters. This is the largest burial chamber in eastern Japan, but the tomb was robbed in antiquity. Remaining grave goods include broken bronze mirrors (shinkyo) indicating a connection with the Yamato dynasty and numerous pottery shards which also indicate a connection with the Kansai region. Other artifacts included swords, spears, iron agricultural implements, jade jewelry and other items. On the outside periphery of the tomb were over 13 smaller circular kofun and over 76 smaller graves from the latter half of the fifth century to the end of the sixth century. The kofun was extensively reconstructed from 1981 to 1992 to restore to what archaeologists consider to be its original appearance, complete with fukiishi and haniwa. The interior is open to the public, and many of the artifacts discovered are on display at the Mori-Shōgunzuka Kofun Museum.

The Ariakeyama-Shōgunzuka Kofun is located on the same ridge as the Mori-Shōgunzuka Kofun, but was much smaller, with a length of 37 meters. It dated from the end of the fifth century to the early sixth century. It was backfilled after a complete excavation survey in 1999, and no trace of it remains today.

The Kurashina-Shōgunzuka Kofun is the third largest kofun in Nagano Prefecture, with a length of 67.7 meters. It was built later than the Mori-Shōgunzuka Kofun and the Ariakeyama-Shōgunzuka Kofun, and was partially demolished to provide building materials for the early Washio Castle in the Muromachi period. It is not open to the public.

The Doguchi-Shōgunzuka Kofun is contemporary with the Kurashina-Shōgunzuka Kofun, dating from the mid-Kofun period. It has a length of 78 meters, and is located on the border between the cities of Nagano and Chikuma. It was excavated from 1982 to 1986.

• List of Historic Sites of Japan (Nagano)

Wikimedia Commons has media related to Mori-shogunzuka-kofun.

• Chikuma city official website (in Japanese)
• Chikuma City official website
• Nagano Prefectural Museum of History website