Hanishina Kofun group

The Hanishina Kofun Group (, Hanishina Kofun gun) is an archaeological site containing three keyhole-shaped burial tumulii from the Kofun period located in what is now part of the cities of Chikuma and Nagano, Nagano Prefecture, in the Chūbu region of Japan. The site was designated a National Historic Site of Japan in 1971. The site includes the Mori-Shōgunzuka Kofun , Ariakeyama-Shōgunzuka Kofun , Kurashina-Shōgunzuka Kofun , and Doguchi-Shōgunzuka Kofun . In addition to the four large tombs which have National Historic Site protection, the surrounding area has many smaller kofun dating from the late fourth to early sixth centuries indicating that this was a center for the pre-Yamato Shinano kingdom. At the base of the hill containing the Mori Shōgunzuka Kofun is the Shinano no Sato Historic Park (, Shinano-no-sato rikishi Kōen) an archaeological park containing faux reconstructions of pit dwellings and raised floor dwellings. It is about 25 minutes on foot from Yashiro Station on the Shinano Railway.

The Mori-Shōgunzuka Kofun is located on a ridge of Mount Ariake at an elevation of 490 meters on the right bank of the Chikuma River, which flows through the southern part of the Nagano Basin in what is now part of Chikuma city. It is the largest zenpō-kōen-fun (which is shaped like a keyhole, having one square end and one circular end, when viewed from above) 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 posterior circular portion is nearly elliptical. The tumulus was once covered fukiishi stones, and had many cylindrical haniwa. The anterior portion has a length of 40 meters and width of approximately 30 meters, with a height of four meters. The posterior circle has a diameter of 45 meters and height of four meters. From the style, it was constructed at the end of the fourth century AD, and is assumed to be the tomb of a local king prior to the establishment of Shinano Province. The mound contains 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 indicating a connection with the imperial 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-type (empun ) 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 Nagano History Museum (, Nagano-kenritsu Rekishi-kan) located at site.

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, and has also been robbed in antiquity. Some small bronze mirrors, pottery shards and beads have been found. It was backfilled after a complete excavation survey in 1999, and no trace of it remains today.

Monument data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).