Yagyū Ittōseki and Amanoiwatate Shrine (柳生一刀石・天石立神社) 柳生一刀石・天石立神社
Local legend attributes the split to Yagyū Muneyoshi, founder of the Yagyū Shinkage-ryū school of swordsmanship, who during his training is said to have cut down a tengu with a single stroke and then found the rock split in two: the parallel with Tanjirō's training scene has made it the spot most photographed by cosplayers. A replica of the sword and a selfie stand have been installed on site, specifically for the visitors who have come since the anime.
A granite boulder measuring 8×7×2 m, split in two by a diagonal crack, about a hundred metres beyond the shrine, at the far end of the Iwatodani valley. Amanoiwatate Shrine is listed in the Engishiki Jinmyōchō, and its divine body is the rock itself.
Nara
柳生東, Yaghu
Demon Slayer: Kimetsu no Yaiba
Local legend attributes the split to Yagyū Muneyoshi, founder of the Yagyū Shinkage-ryū school of swordsmanship, who during his training is said to have cut down a tengu with a single stroke and then found the rock split in two: the parallel with Tanjirō's training scene has made it the spot most photographed by cosplayers. A replica of the sword and a selfie stand have been installed on site, specifically for the visitors who have come since the anime.
All the places from Demon Slayer: Kimetsu no Yaiba
https://theanimetrip.com/luoghi/ittoseki-di-yagyu-e-santuario-amanoiwatate