Stopped by another onsen in the neighborhood (western Tokyo) and it was a win. Presenting Mori-no-Irodori: https://maps.app.goo.gl/q1jgWgM5qFMbMUCv6?g_st=com.google.maps.preview.copy The star of the place is a natural alkaline spring with orange kakenagashi water. On top of all that goodness, the rotenburo is surrounded by dense forest, lots of greenery. Very beautiful and chill. The variety of baths in terms of temperature and types is excellent. Inside they even have electric, herbal, carbonated, and jet baths. Two saunas, very hot, with periodic steam bursts and fan blowing. Of course there's a cold bath. Unusual: a cool (30°?) lying bath outside. A real rarity and pure bliss in summer. All this for 880 on weekdays, and hardly anyone there (I'm guessing it's packed on weekends). Rest area, restaurant, coffee, milk, all the good stuff.