To construct baths as close to the hot spring sources as possible:

Thanks to technological advancement, currently hot springs can be drilled out from great depths, for example, from 1,000m down underground. In ancient times, we people shared hot springs naturally flowing to valleys and other surfaces with wild animals and birds. Still, in Shinkawa Valley hot spring village, we can see natural hot springs upwelling to the ground surface in Wakeyu Onsen or other hot springs along the upstream of Nakatsugawa river.
Hot springs are a living thing. They transform themselves when their temperature or pressure gets
lower or when they are exposed to air. One of the most ideal hot springs probably is the one where the natural hot spring water bubbling from the base of the bathtub. Unfortunately,
such ultimate hot springs are rare.
At Myoken Ishiharaso, a bathroom wing was constructed just next to one of the hot spring sources
and the bath was named “Amoriden.” At this bathroom, hot water at 54℃ is gushing from the depth of 200m underground. In order not to expose the hot water to air before it gets to the outlet for the bathtub, we have worked out a special way to adjust and control the hot water. As the result,
we succeeded to deliver also the ingredients of the hot water without wasting a bit of it. Among others,
we are successfully maintaining carbonic acid abundant in hot spring water of the Myoken Onsen village. Every two years, we conduct an analysis of hot water samples extracted from our hot spring sources
and bathtubs and disclose the result.

Bathtub size suitable for the volume of hot water:

A large and spacious bathroom offers people a refreshing and relaxing time.
If the bathtub does not have a size perfect for the volume of flowing hot water, however,
the water in the bathtub can get unclean and bring health-related concerns. If a bathtub is too large compared to the volume of flowing hot water, some means to complement the volume of hot water
will be necessary including a water circulation system or the addition of hot water or additive agents.
Experts on hot springs say that in order to fulfill health standards, a bathtubful of hot spring water
needs to be replaced with new hot water every one hour.
Which means, we should not construct a bathtub which is too large and cannot be filled up
with hot spring water in one hour. Recently more and more of hot spring facilities are being constructed with too large bathtubs where hot water is circulated or diluted and, quite naturally, the hot water often smells disinfectant chlorine. People are increasingly question about what the ideal hot springs are.
In Shinkawa Valley hot spring village where Myoken Onsen is located, an abundant volume of hot water flows from natural sources.
At Myoken Ishiharaso, 300-litter hot spring water flows every minute directly from the source at
its large common bathroom, Amoriden, whose bathtub can be filled up in one hour. We are proud of
this natural blessing and committed to protect this treasure with great care.