Sesshoseki (Killing Stone)

Sesshoseki, the Killing Stone, is a volcanic rock formation in the Nasu highlands tied to one of Japan's best-known legends, in which the nine-tailed fox spirit Tamamo-no-Mae, after being unmasked as a malevolent shapeshifter at the imperial court during the late Heian period, fled to Nasu and was slain by warriors, her vengeful spirit becoming trapped in the stone and poisoning any bird or animal that touched it, a legend that dates the site's cultural significance to at least the 12th and 13th centuries in surviving folklore and later Noh and Kabuki adaptations. The area historically emitted volcanic hydrogen sulfide gas from nearby vents, a real geological hazard that likely gave rise to the story of animals dying near the stone, linking the legend directly to the site's active volcanic geology in the Nasu range. For centuries the stone was considered cursed and was the subject of Buddhist purification rituals performed by traveling priests, including a documented 14th-century exorcism said to have shattered the stone into fragments scattered across Japan. In March 2022, the main rock at the site split into two pieces, an event that drew national and international attention and was interpreted by some as the legendary seal finally breaking. The surrounding area, part of Nasu Onsen's volcanic terrain, includes a walking path lined with hundreds of small stone Jizo statues and other votive markers placed by pilgrims over the Edo period and into the modern era. Curatorially the site is an open-air natural and legendary landmark rather than a curated exhibition, with a small explanatory sign near the stone summarizing the Tamamo-no-Mae legend for visitors.