N.B. We do not use plural forms for Japanese words, so onsen is always in the singular form.
I have compiled a number of highly regarded onsen from my own private database, along with highlights on Google Maps. The onsen, for those who do not know, is a hotspring. A mineral rich spring that comes up from the earth that people bathe in. In North America, most people snap photos of such places, while here in Japan the locals bathe in them. The hot spring is a source of healing and relaxation that many Japanese travel far and wide to soak in. Some Japanese regard the onsen as a rich part of their cultural heritage, while others just consider it a pastime, something they typically try to enjoy once a year.
There are many icons on my google maps, so what you'll need to do is zoom in closely to whatever area you are interested in. There should be some commentary there about all the places I have visited. This map is a work in progress so as the days and weeks go by I may begin uploading pictures for every single onsen in the list. There are more onsen, believe me. This blog has been a journey for me. Through my travels, I have come to love this country immensely, and sometimes the quirkiness of its people.
The nihonshu, onsen, Jukujo, Japanese cuisine,Tohoku, the distinctive four seasons, Shinkansen, Sea of Japan, Mt. Fuji, and both Yasukuni and Ise Shrines for me are what make Japan great. Other things just pass off as trivial and insignificant when paired up against my own preferences. Again, these are my own choices.
This map should serve as a guide for those who want to experience some of the best hotsprings in Japan. So feel free to leave a comment, either on my blog or on google maps.