is a group of seven archaeological sites located in what is now part of the city of Toyama in the Hokuriku region of Japan. The sites consist of the ruins of a settlement which existed from the late Jōmon period through Kofun period, and several necropolis with numerous kofun burial mounds. The Ōzuka Kofun received protection as a National Historic Site in 1948 and the area under protection was expanded to cover the other six sites in 2005. Outline The site is located in central Toyama Prefecture, in an inland area some 12 kilometers from Toyama Bay on the Sea of Japan at an average elevation of 110 meters. The site is about ten minutes by car from Hayahoshi Station on the JR West Takayama Line. A total of seven areas are covered under the National Historic Site designation: 1. The (45,654 square meters) contains the ruins of a large Yayoi period settlement at an elevation of 35 to 52 meters, overlooking the Nei Plain to the east. Thus far, 25 pit dwellings have been discovered. The dwellings included large circular dwellings (9.5 to 11.5 meters in diameter), square dwellings (6 to 9 meters on each side) and small square dwellings ( 4 to 7 meters on each side). Numerous varieties of Yayoi pottery have been found. The latter half of the Yayoi period was a period of war, which was described in Chinese history books as the Civil War of Wa. Many lowland Yayoi settlement were abandoned, and new settlements were constructed on hilltop locations, with defensive moats, earthen ramparts and wooden palisades. The ruins of many such settlements have been found throughout the Hokuriku region. Although the Senbōyama Site was probably chosen for defensive purposes, no traces of a moat or rampart have yet been found. . 2. The (2,490 square meters)is a rectangular "corner protruding" (Yosumi tosshutsugata funkyūbo) tumulus from the late Yayoi period. This style of tomb was previously found only in the San'in region of Japan. It is located in the southern margin of a river terrace at an elevation of 57 meters near the Senbōyama Site and is believed to be contemporary with that settlement . It measures 24.5 meters on each side, with a height of 5.1 meters, with the protruding portion 7.2 meters long and 10.6 meters wide. Many fragments of Yayoi pottery were found at the site. The presence of such