New York City, New York
A small Japanese-style bathhouse near Union Square with sauna, hot-tub onsen, cold plunge and a recovery lounge, open by reservation only.
$$
Spas with reservation required
3 spas match
Momiji Onsen & Spa
Day SpaKrabi
A moderately priced onsen-style day spa in Ao Nang, Krabi, open daily from late morning into the night.
$$Yufudake Ichibo no Yado Kirara
Hotel SpaYufuin, Oita
A small hillside ryokan near Yufuin's town center where every room has its own half-open-air bath filled with 100% source hot-spring water and a view of Mt.
$$$
