Onsen recommendations?

Hi, I was wondering if anyone could help me with information about natural onsen. I was hoping to find a couple natural onsen that are situated out in natural/wilderness areas that you need to do a bit of hiking to get to and could possibly camp at.
Any help would be appreciated. Thank you.

Consider going to the Shiretoko National Park in Hokkaido. Kamuiwakka-no-taki Falls is a waterfall with 3 levels of natural pools where you can take a dip. You have to hike up 20-30 min. upstream.
http://www.japan-guide.com:80/e/e6851.html

On the east coast of the Shiretoko Peninsula, north of Rausu is Seseki Onsen, a natural onsen right by the sea-shore.
http://puchitabi.jp/hokkaido/article/post-384.html

Also in Hokkaido, by the eastern shore of Lake Kussharo are a few natural onsens:
Kotan Onsen
http://www.masyuko.or.jp/pc/onsen/cotan.html
Ikenoyu Onsen
http://www.masyuko.or.jp/pc/onsen/ikenoyu.html
Sunayu Onsen, you can dig your own pool on the beach.
http://www.masyuko.or.jp/pc/mkk/gourmet/sunayu_rest.htm...