In September of 2020 I went searching for wild & secret Japanese hot springs.
Big note of warning! The wild onsen we went to is found in an area owned by the Nakanosawa Onsen Association. They own the land and you are not supposed to enter past a certain point without a guide from their association. The main reason is because there have been deaths caused by the hydrogen sulfide gasses emitted from the area. They were to be offering an Extreme Onsen Tour starting in 2020, but as far as I can tell that was postponed due to COVID-19.
Onsens we went to in order of appearance
- Bandai Kogen Resort Inn Bonari https://goo.gl/maps/wJYvTiAXLzFs8igX7
- Osakaya https://goo.gl/maps/wcteiDXXg4Fw6h9A9
- Oku-Tsuchiyu Kawakami Onsen https://goo.gl/maps/cJ1wY6wgU9i5Gumy7
- Tsuchiyu Bettei Satonoyu https://goo.gl/maps/eLk3LcwdHSwEkFSN7
Our trip took place in the Mount Adatara and Mount Azuma-Kofuji region of Fukushima and we drove around the Bandai-Azuma Skyline.