Spas with private suites

Daylesford, Victoria

A rammed-earth house on 80 hectares near Daylesford, rented whole for up to 10 adults, with in-room massage and a two-night minimum stay.

Aspen, Colorado

A reservation-only Aspen studio offering private sound, energy and subconscious-journey sessions instead of classic spa treatments.

Baden-Baden, Baden-Württemberg

A Renaissance-era thermal bathhouse in Baden-Baden built in 1877, offering a structured Roman-Irish bathing ritual for about 39 euros a day.

Seattle, Washington

An adults-only wellness studio near Green Lake with private infrared sauna suites, therapeutic massage and red light therapy by reservation.

Sapporo, Hokkaido

Natural hot spring inside Sapporo's Jasmac Plaza Hotel in Susukino, open to day visitors and hotel guests alike, with sauna and a rest lounge.

Bad Wörishofen, Bavaria

Adults-only thermal baths in Bad Wörishofen with palm-house pools, mineral pools and saunas; day passes available, minimum age 16.

Merano, Trentino-South Tyrol

An adults-only, guests-only longevity retreat and hotel spa in Merano with a medical-led wellness institute and private suite treatments.

Scottsdale, Arizona

Adults-only resort spa in Scottsdale with sauna, steam, cold plunge and thermal pools, open only to hotel guests.

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.

Ibusuki, Kagoshima

A ryokan-style hotel in Ibusuki with source hot-spring baths, both shared and private, open only to overnight guests.

Penang

An adults-only villa resort spa near Kepala Batas, Penang, with 18 private villas, spa treatments and plant-based dining; reservation required.