Hot springs in Tsurumaki

Tsurumaki Onsen is a compact hot spring resort in Hadano, Kanagawa Prefecture, roughly 70 minutes by train from Shinjuku. Its waters rank among the most calcium-rich of any hot spring on earth, with concentrations measured at approximately 2,650 mg per kilogram. The Motoyu Jinya inn has operated on the grounds of the former Mitsui family estate since 1917 and remains open today. The resort's size and proximity to central Tokyo make it a practical choice for a half-day excursion.