Near Horokayanto, there are some remains of pit dwellings that were built approximately 1,000 years ago during the Satsumon culture.
These were large aboriginal dwellings on the 15-meter-high Bansei coastal terrace facing the Pacific Ocean. Its length was approximately 2 km from north to south, and there are approximately 130 of them in the surrounding area.
Today, only a pit about 5m in length and 50cm to 1m in depth remains, but a reconstructed dwelling is also on display.
The site is a valuable site for the study of the Satsumon culture, because Satsumon-style earthenware, metalware, and animal skeletons have been unearthed.
The site was designated as a Hokkaido cultural property on July 7, 1966.