Spas with reservation required

Killarney, Munster

A hotel spa in Killarney National Park with an adults-only Vitality Suite of hydrotherapy pool, sauna, steam room and outdoor hot tub.

Napa Valley, California

Adults-only hotel spa in downtown Napa with thermal circuits, sauna, steam and cold plunge, plus massages, facials and medical aesthetics.

Chicago, Illinois

A 5th-floor day spa inside the Palmer House Hilton in the Loop, built around a hydrotherapy circuit, Vichy shower treatments and a facial called Glow Revival.

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.

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

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+.

Idaho City, Idaho

A reservation-only hot springs soak in Idaho City with private tubs, a steam room and a $30 day pass, open five days a week.

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.

Scottsdale, Arizona

Hotel spa inside Hotel Solaya in South Scottsdale built around Tod Miller's proprietary BodyWalking compression technique, with four treatments and a $335

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.

Washington, D.C., District of Columbia

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

Cary, North Carolina

A Cary float center offering sensory-deprivation tank sessions and an oxygen bar, with a 60-minute float running $89.

Utica, Michigan

Single-facility float spa in Utica offering 60-minute sensory-deprivation float pod sessions, walk-ins welcome but reservations recommended.

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.

Raleigh, North Carolina

Single-purpose float spa in North Raleigh offering 60-minute sensory-deprivation pod sessions, open daily with walk-ins accepted.

Washington, D.C., District of Columbia

Day spa in Lanier Heights, DC, offering massage, facials and skincare products, with walk-ins welcome and online booking.

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

Washington, D.C., District of Columbia

A massage, facial and body-treatment day spa in Adams Morgan, open daily 9am–10pm, with couples treatments and no day-pass option.

Washington, D.C., District of Columbia

A Georgetown day spa with 19 treatments, from massage to acupuncture, open daily 9am–10pm with couples options.

Washington, D.C., District of Columbia

A Navy Yard day spa with 19 treatments including massage, facial and body work, open daily 9am-10pm, walk-ins welcome but booking recommended.

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.

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.