Spas with reservation required

Beitou, Taipei

A hot-spring resort in Beitou, Taipei with private suites, outdoor baths and overnight stays, open to day-pass visitors by reservation.

Maui, Hawaii

A nine-room resort spa on Maui's Road to Hana offering lomi lomi and lava-stone pōhaku wela massage, plus a eucalyptus steam room and cold plunge.

Kapaau, Hawaii

An oceanfront eco-boutique hotel and wellness retreat on Hawaii Island's North Kohala coast, open to overnight guests only, not day visitors.

North Royalton, Ohio

A North Royalton day spa built around a salt room and sauna, with adults-only halotherapy sessions on a walk-in or reserved basis.

Austin, Texas

Adults-only resort spa on Lake Austin offering all-inclusive overnight stays and limited day passes to pools, saunas, steam rooms and lake activities.

Las Vegas, Nevada

A Henderson day spa in MacDonald Ranch offering massage, facials and a Himalayan salt lounge, with walk-in and reservation options.

Las Vegas, Nevada

Float tank, massage and salt therapy spot in Peccole Ranch, Las Vegas, open daily with walk-ins accepted alongside bookings.

Ojai, California

A small, independently owned day spa in Ojai offering facials, massage, head spa treatments, infrared sauna and salt therapy.

Park City, Utah

A sauna-and-cold-plunge day spa in Park City with memberships, private group buyouts, and reservation-only access.

Naples, Florida

Day spa in Central Naples with a salt cave for halotherapy, plus massage, facials and yoga classes; walk-ins welcome but reservations recommended.

Nashville, Tennessee

A Gulch studio for infrared sauna and cold plunge sessions in private suites, open daily with reservations required.

Los Angeles, California

A wellness retreat in Westlake's Wilshire corridor offering cold plunge, sauna and movement classes, built around group and community sessions.

Palm Beach, Florida

Salt The Spa is a day spa in Wellington, near Palm Beach, built around a dedicated salt room and newer peptide-therapy treatments.

Pagosa Springs, Colorado

A mobile container-trailer spa in Pagosa Springs offering infrared sauna and cold plunge contrast therapy, adults only, by reservation.

Hudson Valley, New York

An outdoor spa on the Hudson River in Kingston, NY, with two waterfront barrel saunas and garden massage cabins, reservation required.

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.

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.

Catskills, New York

A Catskills retreat center with a Tibetan-style spa offering sauna, steam, pools and cold plunge, built around overnight stays and group programs.

Kyle, Texas

A 88-acre Hill Country resort near Kyle and Wimberley with overnight rooms, a garden spa, pool, hot tubs and day-pass access by reservation.

Asheville, North Carolina

An overnight-stay forest retreat near Fairview with private cedar hot tubs and a shared sauna pavilion session, not a drop-in day spa.

The Hamptons, New York

A moderate-priced, adults-only day spa in Hampton Bays focused on massage, with a salt room and red light therapy, by appointment only.

Bad Blumau, Styria

Rogner Bad Blumau is a Hundertwasser-designed thermal resort in Styria with geothermal pools, outdoor baths and hotel-guest-only access.

Yufuin, 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.

Big Sur, California

Adults-only hotel spa at Ventana Big Sur with ocean-view treatment rooms, outdoor cabanas for couples, and a 24-hour fitness and yoga space.