Spas with reservation required

New York City, New York

A below-street-level day spa in NoHo with thermal baths, a three-story indoor waterfall, sauna, steam room and cold plunge, plus massage and facial treatments.

Seattle, Washington

A Bellevue day spa in Wilburton specializing in head spa scalp treatments, massage, facials and couples sessions, with free on-site parking.

Palm Beach, Florida

A straightforward day spa on North Military Trail in West Palm Beach offering massage and reflexology, open daily with walk-ins taken.

Los Angeles, California

A women-focused Korean day spa in Pico-Union with steam, salt and ice rooms, open daily 9am to 9pm, with massage and facials open to men too.

Naples, Florida

Adults-only day and medical spa in Old Naples offering massages, facials and monthly Botox/filler visits from Dr. Keamy, with a $155 signature facial.

Scottsdale, Arizona

A moderately priced day spa in South Scottsdale with lake-view suites, massage and facials, plus a dedicated couples treatment room.

Miami, Florida

A Peruvian-themed day spa inside the Victor Hotel on Ocean Drive, South Beach, with a hamam, steam room, sauna and a couples suite.

Boston, Massachusetts

A Finnish kelo-log banya in Newton with sauna, steam room and cold plunge, alternating men's and women's days, day passes from $69.

Miami, Florida

Nature-themed day spa in Brickell with hydro massage, a hydrotherapy circuit and couples treatments, open daily 9am-6pm.

Chicago, Illinois

Hotel spa on the lower level of the Fairmont Chicago, open to guests for massages, facials and a couples suite with an infinity-edge soaking tub.

Seattle, Washington

A Renton day spa built entirely around scalp and hair rituals, using water-dome treatments and three tiered packages from $75 to $120.

Scottsdale, Arizona

Day spa in South Scottsdale offering massage, facials and body treatments, with walk-ins and couples appointments by reservation.

Tucson, Arizona

A moderate-priced day spa in Tucson's Tangerine Acres neighborhood offering four treatments, an aromatherapy blending bar and vegan manicures, open daily

Indianapolis, Indiana

Day spa in Allisonville, Indianapolis with sauna, steam room, thermal pool and cold plunge, plus about 10 massage and facial treatments for solo visits or

Miami, Florida

An upscale day spa on Miracle Mile in Coral Gables with sauna, steam room and cold plunge, known for a $200 signature treatment and couples packages.

Napa Valley, California

A family-run day spa in Vacaville near Napa Valley, offering massage, facials, waxing and a private whirlpool tub by appointment only since 1997.

Napa Valley, California

A downtown Napa day spa offering massage, facials, lymphatic sculpting and sauna treatments, with walk-ins welcome and on-site parking.

Scottsdale, Arizona

North Scottsdale day spa with massage, facials, sauna, steam and a thermal pool, plus private suites for couples and groups.

San Francisco, California

Hotel spa at The Huntington Hotel on Nob Hill with a heated soaking pool, sauna, steam room and terrace, open daily 8am-7pm; treatment booking required.

Hudson Valley, New York

A Newburgh day spa built around a Japanese head spa signature treatment, with massage, sauna, steam room and pool access, open seven days a week.

Portland, Oregon

Day spa in Vancouver, WA near Portland, offering facials, massages, scrubs and waxing, with a $180 Platinum Hydrating Facial as its signature treatment.

Palm Springs, California

Adults-only hotel spa at the Parker Palm Springs with 15 private treatment rooms, couples suites and a $300 signature aloe treatment.

San Francisco, California

Women-only Korean-style bathhouse and day spa in Japantown, San Francisco, open daily by appointment, clothing-optional.

Hudson, New York

Adults-only communal thermal baths and steam room in downtown Hudson, NY, with day passes, memberships and treatment-plus-soak packages.