Spas with reservation required

San Diego, California

Resort spa on Mission Bay offering massages, facials and body treatments, with walk-ins welcome and a gym and yoga classes on-site.

Aspen, Colorado

Ski-in/ski-out hotel spa in Aspen with three private treatment suites, 15 treatments, and booking required by phone or email.

Asheville, North Carolina

Adults-only hotel spa in Asheville with a fiber-optic-starred lap pool, waterfall pools, saunas and an electronics-free policy; day passes are limited and

Houston, Texas

A 20,000-square-foot hotel spa in Houston's Westside offering a biohacking facial machine, hydrotherapy circuit and co-ed relaxation lounge, by appointment

Miami, Florida

Hotel spa at The Ritz-Carlton Key Biscayne, Miami, with treatment suites, sauna, steam room and whirlpool, open to hotel guests 18 and up by appointment.

Aspen, Colorado

Hotel spa at Viceroy Snowmass in Aspen with 20 treatments, a plunge pool and couples massage rooms, open daily 10am-6pm by reservation.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

Santa Fe, New Mexico

Small hotel day spa in downtown Santa Fe with a soaking pool, five treatment rooms and 25 services, open daily 8am-5pm by reservation.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Aspen, Colorado

Adults-only hotel spa at Viewline Resort Snowmass with a $25 day pass, steam rooms, outdoor pool and whirlpool, reservations required.

Sedona, Arizona

Adults-only resort spa in Sedona with outdoor hot tubs, steam rooms and a 30-treatment menu, open daily with walk-ins and day passes.

Portland, Oregon

A 21-and-up day spa in Portland's Irvington neighborhood built around vinotherapy, with wine-infused baths, massages and Caudalie facials.

Chicago, Illinois

A moderately priced day spa in Chicago's Lakeview neighborhood focused on Chinese-style head and scalp treatments, open to adults 16 and up.

Pittsburgh, Pennsylvania

A South Hills float center offering sensory-deprivation float tanks alongside sauna and cold plunge, with a 60-minute float starting at $89.

Washington, D.C., District of Columbia

A float therapy studio in Alexandria offering sensory-deprivation floats, sauna, cold plunge, and red light therapy sessions.

Cedar Park, Texas

Cedar Park float spa offering sensory-deprivation float therapy plus sauna, steam room and cold plunge, open daily 8am-10pm.

Austin, Texas

Float tank spa in South Austin's South Lamar area offering sensory-deprivation floats, sauna and cold plunge, with walk-ins welcome.

Indian Land, South Carolina

Float therapy center in Indian Land, SC (serving Charlotte and Fort Mill), offering 60-minute sensory deprivation floats plus an oxygen bar.

Palm Springs, California

A 16-room adults-only hotel in Desert Hot Springs with three natural mineral-water pools fed by a 350-foot geothermal well, plus a small on-site spa and

Key West, Florida

A medical spa in Key West offering Morpheus8, injectables and body contouring, with a sauna, steam room and thermal pool on site by appointment only.

Asheville, North Carolina

A small massage-focused day spa in downtown Asheville offering Swedish, deep tissue, Thai yoga and prenatal massage, open daily 9am-8pm by reservation.

Miami, Florida

Hotel spa at The Setai in Miami Beach with 7 ocean-view treatment rooms, 5 couples suites, saunas, steam and a cold plunge.

San Diego, California

A Bankers Hill medical spa in an 1887 Victorian house, focused on HydraFacials, acne treatments and facials with its own in-house skincare line.

Austin, Texas

Hotel spa inside Austin Proper with 15 treatments, a cold plunge and sauna recovery room, open daily by reservation.