Tokyo Somei Onsen Sakura

Though it's best visited during cherry blossom season, when the somei-yoshino trees on the premises are at their finest, this onsen bathhouse has enough going for it to be worth a look any time of year. The sodium chloride-rich waters may not be much different to what you'd find at many other baths in the city, but at Sakura they're filtered to remove the colour and smell. The elegantly appointed facilities also include a stone sauna (reservation required).