Spas with luxury

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

Kurokawa Onsen, Kumamoto

A nine-room ryokan in Kurokawa Onsen where every detached suite has its own source-fed open-air bath, open to overnight guests only.