These tumuli date from the 4th to 6th century AD and were discovered during the construction of a highway bypass connecting the Hokuriku Expressway with Japan National Route 8, during which time a number of other archaeological discoveries were made, including the Yoshikawa Site, a Yayoi period settlement, and the Kotanigahora Kofun Cluster; however, neither of these sites received government protection and were totally destroyed during highway construction after a hasty compliance excavation.

Grave goods found include weapons such as swords, spearheads, and fragments of gold-plated armor and helmets, bronze mirrors, and agricultural implements.

[2] The weapons in particular are considered to be rare examples nationwide, and have been preserved since 2010 at a private folk museum in Tsuruga.

The tumuli are about 15 minutes by car from Tsuruga Station on the JR West Hokuriku Main Line.

[2] This site consists of three surviving circular-type kofun [ja] (empun (円墳)) on a hilltop ridge in the Yoshikawa neighborhood of Tsuruga.