Kanayama Megaliths
Ancient people living in what is now the Kanayama area during the Jomon period (10,000–300 BCE) may have made use of giant rocks to track the seasons and years. These rocks, known as the Kanayama Megaliths, encompass three different rock formations (Iwaya Iwakage, Senkoku, and Higashi no Yama) standing some distance from each other. The megaliths are located a 30-minute drive west of Gero’s hot spring district.
Local researchers assume, based on the megaliths’ distribution and distance from each other, as well as markings on them, that they functioned as a kind of enormous solar calendar. The rocks may have been used to track the seasons by observing how the sun’s rays fell on them at different times of the year, allowing the calendar-keepers to determine the timing of the solstices and equinoxes.
Remains of dwellings and tools dating back about 8,000 years have been found in the area, leading researchers to theorize that the ancient inhabitants of Kanayama placed the megaliths here intentionally to keep track of time.
Conclusive proof for this theory is yet to be established in the field of archaeoastronomy, which combines the study of archaeology, geology, and astronomy, but the Kanayama Megaliths still make for an exciting and thought-provoking excursion from Gero. The Kanayama Megaliths Research Center and Gallery offers guided tours of the mysterious rocks.