Excavated Items from the Grave Pit at the Tokoro River

Artifacts from Burial Pits at the Tokoro River Estuary Site: Treasures of Ancient Hokkaido

On the northeastern coast of Hokkaido, where the Tokoro River meets the icy waters of the Sea of Okhotsk, lies one of Japan's most remarkable archaeological discoveries. The "Artifacts from Burial Pits at the Tokoro River Estuary Site" (北海道常呂川河口遺跡墓坑出土品) is a collection of 1,805 burial goods designated as an Important Cultural Property of Japan in June 2023. These extraordinary objects — amber necklaces strung with thousands of beads, jade magatama curved pendants, finely decorated pottery, and obsidian tools — offer a rare window into the spiritual world and daily life of the people who lived along the Okhotsk coast between approximately 2,900 and 1,600 years ago.

This collection represents the only nationally designated Important Cultural Property currently held in Kitami City, making it an essential destination for visitors seeking authentic encounters with Japan's deep archaeological heritage far from the crowds of more famous sites.

The Tokoro River Estuary Site: A Crossroads of Ancient Cultures

The Tokoro River Estuary Site is located on a slightly elevated area near the mouth of the Tokoro River, the largest river flowing into the Sea of Okhotsk from Hokkaido. Archaeological excavations, conducted from 1988 to 2002 as part of a river improvement project to straighten a meandering section, revealed an extensive communal cemetery used from the Late Jomon period through the Epi-Jomon period (続縄文時代).

The Epi-Jomon period is a cultural phase unique to Hokkaido. While mainland Japan transitioned to rice-based Yayoi culture, the people of Hokkaido continued a hunting, fishing, and gathering lifestyle that evolved from the earlier Jomon tradition. This makes the Tokoro River Estuary Site particularly significant for understanding a cultural trajectory that diverged from the rest of the Japanese archipelago.

The excavations unearthed numerous burial pits containing an astonishing variety and quantity of grave goods. The 1,805 items selected for Important Cultural Property designation are representative pieces from this vast collection, chosen to illustrate the richness and diversity of ancient burial practices in eastern Hokkaido.

Why Were These Artifacts Designated an Important Cultural Property?

The designation as an Important Cultural Property recognizes several aspects of this collection's exceptional value. Firstly, the sheer scale and diversity of the burial goods are unmatched among comparable sites in Hokkaido. The artifacts include pottery of remarkably ornate and sometimes unusual forms, large quantities of stone arrowheads, spherical and rod-shaped obsidian raw materials, and an extraordinarily rich array of personal ornaments.

Among the most notable items are amber beads, believed to have been sourced from Sakhalin Island to the north, suggesting that the inhabitants of this region controlled important trade routes along the Sea of Okhotsk coast. One particularly impressive burial, known as Pit No. 470, contained approximately 2,500 amber beads — a quantity unmatched at any contemporary site across all of Hokkaido. This discovery points to the existence of powerful individuals or families who commanded far-reaching exchange networks.

The collection also includes jade (jadeite) magatama and beads transported from the Itoigawa region of Niigata Prefecture, over 1,000 kilometers to the south. The presence of both northern (Sakhalin amber) and southern (Niigata jade) luxury materials in a single site vividly demonstrates the extensive trade connections maintained by these ancient coastal communities.

Collectively, these artifacts provide indispensable evidence for understanding the cultural practices, social organization, and funerary rituals of eastern Hokkaido from the Jomon through the Epi-Jomon periods, making them invaluable to the study of Japanese prehistory.

Highlights of the Collection

Where to See the Artifacts: Tokoro Forest Park of Archaeological Sites

The Important Cultural Property artifacts are exhibited at the Tokoro Archaeological Museum (ところ遺跡の館), the central exhibition facility within the Tokoro Forest Park of Archaeological Sites (ところ遺跡の森). This park is part of the nationally designated historic site known as the Tokoro Site, one of the largest prehistoric settlement complexes in all of Japan.

The museum presents the artifacts chronologically, allowing visitors to trace the evolution of burial practices and material culture from the Jomon period through to the Ainu cultural period. In addition to the designated Important Cultural Property items, the museum displays artifacts from the broader Tokoro Site excavations, including Okhotsk culture pottery, bone tools, and Satsumon-period materials.

Within the forest park grounds, visitors can also explore reconstructed pit dwellings set among actual archaeological remains — shallow depressions in the earth that mark the locations of ancient houses. Walking among these 138 identified dwelling sites, some dating back 4,000 years, offers a powerful sense of connection to the people who once lived here.

Two additional exhibition facilities are located nearby: the Tokoro Buried Cultural Property Center (free admission) and the University of Tokyo Archaeological Gallery (free admission), which displays materials from over 60 years of academic excavations in the area.

Exploring the Surrounding Area

The Tokoro area offers a wealth of natural and cultural attractions that pair wonderfully with a visit to the archaeological museum.

Directly adjacent to the park is the Wakka Wild Flower Garden (ワッカ原生花園), a designated Hokkaido Heritage site and one of Japan's largest coastal grasslands. Stretching approximately 20 kilometers along a narrow sandbar between the Sea of Okhotsk and Lake Saroma, this remarkable natural area hosts over 300 species of wildflowers. From late May through October, visitors can explore the garden by rental bicycle from the Wakka Nature Center.

Lake Saroma, Japan's third-largest lake and the largest in Hokkaido, is renowned for its stunning sunsets and its production of scallops and oysters. The lake's distinctive blue color, known locally as "Saroma Blue," is best appreciated from the Horoiwa Mountain observation point.

For those interested in further archaeological exploration, the Moyoro Shell Mound Museum in nearby Abashiri City (approximately 45 minutes by car) offers insights into the Okhotsk culture, while the Hokkaido Museum of Northern Peoples provides broader context about the indigenous cultures of northern regions worldwide.

The Saroma Lake Tsuruga Resort, located directly across the street from the forest park, offers comfortable accommodation for visitors wishing to spend more time exploring the area.

Practical Information for Visitors

The Tokoro Forest Park of Archaeological Sites is accessible by car from Kitami city center (approximately 1 hour) or from Abashiri (approximately 45 minutes). The nearest airport is Memanbetsu Airport (Okhotsk Monbetsu Airport), about 1 hour by car. A municipal bus service operates between Kitami and the Sakaeura area, with the park located a short walk from the Sakaeura bus stop.

A smartphone-based self-guided tour is available in multiple languages including English, Simplified Chinese, and Traditional Chinese, making the exhibits accessible to international visitors even without a Japanese-language guide. For group visits, advance arrangements can be made for guided tours by the museum's curators.

Visitors during the warmer months (late May through October) should note that mosquitoes can be prevalent in this coastal area. Insect repellent and long-sleeved clothing are recommended.