I've just spent a lovely few days in the Kii peninsula, in Wakayama, Japan. We stayed in traditional guest houses, in onsen towns along the Kumano Kodo ancient pilgrimage route. Our first stay was in Yunomine.
The tiny public onsen 'tsuboyu' there is the only UNESCO world heritage recognised hot spring! After enjoying that, and cooking our own onsen eggs, we walked part of the Kumano Kodo, over a mountain, enjoying the moss and ferns.
I love the combination of lush green, tall trees, and ancient stones.
We then stayed at the delightful Kameya Ryokan in Kawayu Onsen, on the Ota river.
We sat on the rocks and swam in the river, where the cold running water mixed with the bubbling hot spring water rising up through the stones.
I love onsen holidays!