It is identified as one of the oldest forward-rear (keyhole) burial mounds in the Nagano Prefecture.
The tumulus dates back to the early Kofun period, specifically the 4th century AD.
Archaeological digs at the site uncovered a rare 'triangular-rimmed mirror' with divine beast decorations.
Approximately 2,000 cherry trees of various species are planted along the walking paths of the hill.
The site acts as a vantage point for observing the Kamikochi and Norikura peaks of the Northern Alps.
Koboyama Tumulus is a 4th-century burial mound located in Matsumoto, recognized as one of the oldest keyhole-shaped kofun in eastern Japan. Situated on the summit of a hill, the site measures approximately 130 meters in length. It is renowned locally for its extensive population of cherry trees, which transform the landscape during the spring season. Excavations at the site have yielded significant archaeological findings, including bronze mirrors and iron weaponry. The elevation provides panoramic views of the Matsumoto Basin and the surrounding Northern Alps. The tumulus is preserved as a historical site and serves as a public walking area for local residents and visitors.
The summit path provides a framed shot of cherry blossoms in the foreground with the snow-capped Northern Alps in the distance.
Wear comfortable, flat walking shoes to navigate the earthen paths and hillside incline.
Bring a portable cushion or mat if you intend to sit under the trees during peak season.
Pack out all your trash as there are limited public waste facilities on the hill.
Attempting to visit during mid-summer afternoons as there is limited shade away from the trees, and avoiding the site during heavy rain when trails become slippery.
Stay on marked walking trails to protect the structural integrity of the burial mound; do not climb on the burial mound itself.
