An unusual beach where the dark sand is heated by volcanically heated spring water below. To take advantage of the relaxing and rejuvinating properties of the sand, people are buried up to the neck and left for around 10 minutes. The bath costs around 1,000 yen and you can opt for more heat and weight (i.e more sand) if you so wish. The town is famous for regular onsen too, so after having a sand bath you can have a regular one too.