So-un hot springs

So-unzen onsen is one of the 20 hot springs scattered across Hakone, outside of Tokyo. So-unzen's best kept secret is the hot springs at Saijo-ji Hakone Betsuin, near So-unzen station. So-unzen's water is sulfur-based and is said to be good for nerve and muscle pain. It is also rich in iron and said to be beneficial to the skin and improves poor blood circulation.  As of April 2019, the bath at Saijo-ji Hanoke Betsuin does not accept day visitors.