Tobayama Cave: A Jomon-to-Edo Archaeological and Burial Site in Japan
Site at a Glance
- Rating
- 3.6
- Popularity
- Very Low
- Country
- Japan
- Primary era
- Classical
- External website
- Open
- Eras represented
- Stone Age, Classical
- Civilizations
- Jomon, Yamato
- Site type
- Burial
- Remains
- Necropolis
On this page11 sections
History
Tobayama Cave is a composite archaeological site in Ueda, Japan, with evidence of habitation and burial from the Jomon period through the Kofun period and into the Edo period. The Jomon period encompassed Japan’s prehistoric hunter-gatherer and early settled communities, while the Kofun period was an age of large burial mounds and powerful regional societies. The cave’s principal historical importance lies in its middle Kofun-period funerary use, when people placed bodies inside the cave for exposure burial, also called wind burial, rather than interring them in the ground.
Discovery and excavation
In April 1966, Koichi Seki, a teacher and archaeological investigator at Maruko Industrial High School, found large quantities of pottery scattered through the cave during an investigation with students. The school is now called Maruko Shukan High School. At Seki’s initiative, the former Maruko Town Board of Education established an excavation team led by Seki and Koichi Nagamine, a professor at Kokugakuin University. Students and researchers from the high school, Kokugakuin University, and Nihon University took part.
Three excavations followed, from July 25 to 31, 1966, July 25 to August 3, 1967, and July 28 to August 3, 1968. They revealed evidence from widely separated periods, including the Jomon and Kofun periods, the Edo period, and probably the Yayoi period. The Yayoi period is associated with wet-rice agriculture, metal use, and growing social differences in ancient Japan.
Kofun-period funerary use
During the middle Kofun period, the cave served as a place for funerary practices. Human bodies were placed inside it without conventional burial, and large quantities of bones and pottery offerings remained across the prepared floor. The burial group has been interpreted as possibly belonging to local clans that did not build kofun, the large burial mounds associated with influential ancient Japanese groups.
Comparable exposure-burial practices are known from coastal caves in Wakayama, Kanagawa, and Chiba, as well as from Southeast Asia and Okinawa, but they are rare on mainland Honshu. Seki proposed that these similarities might indicate the movement of a maritime group into the inland area of the former Chiisagata District in Nagano. This remains an interpretation rather than an established conclusion.
Edo-period activity and later recognition
People entered the cave again during the Edo period. Human bones found with Kan’ei Tsūhō coins, copper currency issued in Japan during that period, and wood-shaving sutras, Buddhist texts written on thin shaved wooden strips, came from an area where part of the earlier paving had been moved. Nagamine suggested that people compelled to live apart from settled communities may have stayed there. This interpretation was linked to the local name “Katteiwa,” understood as a possible corruption of a term referring to people affected by leprosy.
The site was designated a prefectural historic site in 1972 under the name “Tobayama Cave Site” and became a National Historic Site of Japan in 1978. Its excavated artifacts are designated as Nagano Prefectural Treasures. Materials from the excavations are displayed at the Ueda City Maruko Cultural Museum.
Remains
Tobayama Cave opens westward from shale-bearing conglomerate on a cliff on the western slope of Mount Toba. It stands at an elevation of 843.9 meters, about 15 meters above the bed of the Yoda River, which flows into the Chikuma River. The opening is approximately 25 meters wide and the cavity extends about 15 meters inward. Because the opening is wider than the interior depth, the site has the form of a semi-cave rather than a deep cavern. Its local name was “Katteiwa.”
Jomon and Kofun-period installations
Jomon paved building
At the northern end of the lowest terrace, excavators found a paved building dating to the late Jomon period, together with Jomon pottery. Pottery from an earlier part of the Jomon period was also identified. Layers below the excavated level were thought to contain earlier artifacts and structural remains, but work stopped to protect the important Kofun-period paving above them.
Terraced funerary floor
The principal Kofun-period installation consists of four steps that create five terrace surfaces. The floor rises in stages from the rear of the cave toward the entrance. Flat cobbles from the Yoda River densely cover the terraces in a fan-like arrangement, creating the prepared setting for the funerary activity.
Burial contexts and offerings
Human bones and pottery offerings were scattered across the paved terraces. They belonged to three Kofun-period contexts or layers, one of which contained several sets of crushed bones. In a squared-off space at the rear, more than ten individual Haji vessels had been placed upside down. Haji ware is unglazed earthenware pottery, while Sue ware is high-fired ceramic pottery introduced during the Kofun period and often associated with funerary and elite settings.
Objects associated with the burials
The Kofun-period finds include Haji and Sue pottery, iron weapons, horse fittings, tools, whetstones, steatite imitations, small glass beads, koto-bridge-shaped stone objects, stone bracelets, and copper bracelets. Some objects were associated with particular human remains, while the relationship between other finds and individual remains is uncertain. Particularly well-preserved ritual objects include a double-necked Sue flask and an iron sword that had been deliberately bent.
Later disturbance
Part of the Kofun-period paving was moved during later activity in the cave. The disturbed area contained Kan’ei Tsūhō coins, wood-shaving sutras, and human bones, providing physical evidence of Edo-period use. The excavated artifacts are housed and displayed at the Ueda City Maruko Cultural Museum rather than remaining as features of the cave itself.
