What makes Torihama extraordinary is not what its inhabitants built but what they threw away. The midden extends from seven meters underground to three meters above the current surface, a thick stratigraphy of cultural deposits spanning thousands of years. Because the refuse accumulated in the shallows of Lake Mikata, oxygen-depleted water and saturated sediment prevented the organic materials from decomposing. Ropes, reed baskets, wooden combs, stone axes, and net weights all survived intact. Three pit dwellings were detected on the southern slope of Shiibayama Hill, confirming that a settled community lived here -- not just seasonal visitors but people who stayed, season after season, building a life between the lake and the forested hills of the Wakasa Wan Quasi-National Park.

In 2011, radiocarbon dating confirmed that a lacquer tree fragment excavated from Torihama is 12,600 years old -- the oldest lacquer tree discovered anywhere in the world. Lacquered pottery and combs found at the site represent the oldest known examples of Japanese lacquerware, a craft tradition that continues to this day. Alongside the lacquer, excavators uncovered what may be Japan's oldest fabric: a rope woven from hemp fibers, dating back 12,000 years. Woven plant fiber items made from Boehmeria tricuspis were also found. These discoveries, investigated by scholars from Tohoku University between 1984 and 2011, pushed back the timeline of Japanese material culture by millennia and demonstrated that Jomon people possessed sophisticated manufacturing skills far earlier than previously assumed.

Torihama challenged the conventional narrative that Jomon people were purely hunter-gatherers. The site yielded evidence of cultivated beefsteak plant (perilla), bottle gourd, hemp, paper mulberry, burdock, and mustard family plants. Acorns, walnuts, chestnuts, water chestnuts, red beans, melon, and Chinese cabbage rounded out a diverse diet in which plant foods accounted for roughly half the caloric intake. This was not the agriculture of paddy fields and irrigation canals -- it was a careful, deliberate management of wild and semi-domesticated species that blurred the line between foraging and farming. Skeletal remains of the now-extinct Japanese wolf, dating from 10,000 to 250 BC, suggest the inhabitants also lived alongside these animals, possibly in an early form of domestication.

In 1981, excavators found several dugout canoes buried in the mound. The oldest, dated to approximately 3,500 BC, was the oldest canoe ever discovered in Japan at the time. Roughly six meters long and carved from a single Japanese cedar trunk using fire and stone adzes, it spoke of a community intimately connected to the water. Lake Mikata and the surrounding lakes would have been highways for these people -- routes for fishing, trade, and communication with other settlements along the coast of Wakasa Bay. Today, the majority of the artifacts from Torihama are housed at the Wakasa Mikata Jomon Museum in Obama, about 20 kilometers west of the site. The canoe, the lacquered combs, the hemp rope, and the stone tools sit behind glass, quiet witnesses to a community that flourished here for seven millennia.