Hot springs that remain intact Hidden hot spring list(Tokyo) [Hot springs deep inside Japan]

List of Hot springs in Japan that remain intact or a little bit artificial or artificial with some recomendations.
sangakuonsen.com (*Writen in Japanese.)

sangakuonsen.com (*Writen in Japanese.) for the location of a Mountain on Google map.

(Caution!)
H2S gases or a Bear can be conflict at the site listed below.Please keep out those sites,even if at your own risk. (Must see if you don't know the risk of H2S or anoxia at all. written in Japanese.) anoxia/H2S-Helth department Japan
(*)number of astarisks represents impression. The list of Ryokans with hidden onsen or not known much.