The Tokachi Horokayanto Pit Dwelling Cluster is a large residential settlement of an indigenous people, built on the Bansei coastal terrace facing the Pacific Ocean at an elevation of 15 meters. It stretches for approximately 2 km from north to south, and there are over 130 such sites distributed in the surrounding area.

As for the artifacts, Satsumon-style pottery is the main type, and a small number of obsidian stone tools have been excavated along with the pottery. Additionally, stone sinkers thought to be for fishing made by slightly modifying natural stones, numerous small stones believed to have been used as weights for weaving mats, corroded iron fragments thought to be pieces of metal tools, and animal skeletons have been unearthed.

A characteristic of this site is the small number of both pottery and stone tools and the fact that metal tools have been unearthed. The excavation of Okhotsk-style pottery is also noteworthy. It is believed that during the Satsumon culture period, the use of stone tools had already declined, and metal and wooden tools were widely used. These historic sites were designated as a Hokkaido Historic Site on July 7, 1966.