Spas with reservation required

Lake Tahoe, California

A massage-and-facial day spa in South Lake Tahoe's Heavenly Village, open daily 10am-9pm, with couples treatments and a signature package at $320.

Las Vegas, Nevada

Adults-only hotel spa inside Westgate Las Vegas offering massages, facials, salon services, sauna, steam room and a thermal pool, open daily 9am-6pm.

San Francisco, California

Valencia Street studio in Dolores Heights focused on lymphatic body sculpting and facials, including its signature Face Sculpt.

Naples, Florida

A small, moderately priced day spa in East Naples offering massage and a sauna, open daily with walk-ins accepted.

Asheville, North Carolina

A Japanese-inspired destination spa on a mountainside outside downtown Asheville, built around private outdoor salt hydrotherapy tubs and massage.

Sierraville, California

A non-profit hot springs retreat near Lake Tahoe with natural spring pools, reservation-only day and evening soaks, camping and rooms, closed Mondays and

Carmel-by-the-Sea, California

Upscale day spa in Carmel-by-the-Sea's Golden Rectangle with sauna, steam, cold plunge and thermal pools, open daily from 6:30am.

Denver, Colorado

A three-room day spa in Five Points offering massage, facials and head spa treatments, reservation only, with a signature 80-minute massage-facial combo.

Mumbai, Maharashtra

An upscale Ayurvedic retreat in Vile Parle West, Mumbai, with five treatments, couples rooms and a relaxation lounge; reservations required, open daily

Santa Barbara, California

A downtown Santa Barbara day spa built around a private infrared sauna, salt room, cold plunge and a sound-and-light meditation pod, booked by appointment.

Austin, Texas

Adults-only hotel spa at the Fairmont Austin with nine treatment rooms, a hydrotherapy circuit, sauna and cold plunge, open daily with day passes available.

Miami, Florida

A small treatment-focused day spa in South of Fifth, Miami Beach, offering massages, facials and body scrubs with walk-in slots available.

Carmel-by-the-Sea, California

Resort spa at Carmel Valley Ranch with 12 treatment rooms, private terraces, a saltwater pool and infinity hot tub, open to adults by reservation.

San Diego, California

Adults-only day spa at Mission Bay Resort with massage, facials, Himalayan salt treatments and couples suites; walk-ins and day passes welcome.

Santa Barbara, California

A small downtown Santa Barbara day spa off State Street offering waxing, facials, massage and skin treatments, with online booking required.

Lake Tahoe, California

Adults-only hotel spa at Edgewood Tahoe with gemstone massage rituals, an oxygen bar, and treatment-only access to the facility.

Palm Springs, California

Hotel spa at the Renaissance Esmeralda in Indian Wells offering desert-inspired treatments, a recovery lounge, steam rooms and day passes, adults only.

Nashville, Tennessee

A Berry Hill day spa in Nashville offering massage, facials, body treatments and a sauna pod/salt room, open Tuesday through Saturday.

Philadelphia, Pennsylvania

A small reservation-only day spa in Center City East Philadelphia offering facials, massage, and lash and brow services.

Piešťany, Trnava Region

Spa Irma on Piešťany's spa island offers historic mud and mirror thermal pools, a hydrotherapy circuit and a 60-treatment medical spa menu, adults only.

San Francisco, California

Day spa on the 17th floor near Union Square offering massage-focused treatments, open daily 10am-8pm with walk-ins accepted.

Castle Rock, Colorado

A small day spa studio in Castle Rock offering massage, facials, waxing, lashes, brows and permanent cosmetics by appointment.

Palm Springs, California

Adults-only hotel spa at Tommy Bahama Miramonte in Indian Wells with 15 treatments, eucalyptus steam rooms, a hydrotherapy jacuzzi and saltwater pool.

Portland, Oregon

A reservation-only med spa and day spa in downtown Portland offering massage, facials and med spa treatments, plus monthly memberships.