Benten Kousen

Benten Kousen is a small hot spring inn on the coast of Kowaura in Minamiboso City, Chiba Prefecture, on the Uchibo side of the Boso Peninsula. According to local legend, Minamoto no Yoritomo, fleeing to Awa Province after his defeat at the Battle of Ishibashiyama in 1180, purified his hands at a pond near what is now Itsukushima Shrine and witnessed a divine manifestation of Benzaiten there, and the spring takes its name from this goddess. The inn is said to have opened in the 1960s and moved to its current site in 1969, and today it welcomes only four groups of guests per day.

The source water emerges at a cool 14.2°C and is warmed to around 42.4°C for the indoor bath. It is a sulfur spring (hydrogen sulfide type) containing sulfur, hydrogen sulfide, and boric acid, and its water is famous for changing color: milky white, pale green, and jade are the three base tones, shifting through intermediate shades over the course of the day. Rather than recirculating the water, the inn drains and refills the bath with fresh source water every day using an overflow method, which is said to be what allows the color changes to be observed.

There is a single open-air bath shared between men and women on a time-rotation basis, with views of Tokyo Bay and, on clear days, Mount Fuji. Day-trip bathing is available from 10:00 to 15:00 on a one-hour private reservation basis (advance booking required), priced at 2,000 yen for adults (bathing tax extra), with bathing-only entry free for middle school students and younger. The inn has 11 guest rooms and is also known for meals featuring fresh local seafood.