Ōmuro Kofun group


Ōmuro Kofun Group is a group of late Kofun period burial mounds located in what is now part of the city of Nagano in the Chubu region of Japan. The site was collectively designated a National Historic Site of Japan in 1997.

Overview

The Ōmuro Kofun Group is a large necropolis consisting of over 500 tumuli spread across two valleys in the Matsushiro neighborhood of Nagano city. The tombs were built over a 250-year period from the 5th to the 8th centuries, and have been grouped by archaeologists into five groups by their geographic location.
There is only one keyhole-shaped kofun, but at least 330 smaller dome-shaped kofun made of stacked river stones from the Chikuma River. Most of these dome-shaped kofun have a diameter of approximately 10 meters, and there is no other burial mound cluster in Japan where there are so many such dome-shaped kofun in such a small area. These mounds can be divided into 40 different variations, some with a scallop-shaped stone burial chamber, or with a triangular gabled burial chamber ceiling. Theories that these tombs were built by immigrants to Japan from the ancient Korean states of Goguryeo or Baekje remain controversial.
The 2.5 square kilometer site is now an archaeological park with a museum displaying some of the artifacts discovered.

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