Natural hot spring Heiwajima is a experience in Ota Ku, Tokyo. 1 YouTube travel vloggers — including 地理ふしぎ発見【ゆっくり解説】 — have covered it across 1 clips.
“[678.5s] Next up is the Yanglao Warning Hot Spring, located along the Yanglao River, which spans Ichihara City and Oki Town in Chiba Prefecture.”