Spas with outdoor baths

Tucson, Arizona

Adults-only hotel spa at El Conquistador Tucson with a salt therapy lounge, heated outdoor pool and mountain views, day passes available to hotel guests.

Ibusuki, Kagoshima

Oceanfront outdoor onsen in Ibusuki where the two gender-assigned baths swap daily, with views of Mount Kaimon, the East China Sea, and Take-yama.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

Los Angeles, California

Four Seasons hotel spa in Beverly Hills with a steam room, rooftop pool, fitness center and eight treatments, open daily, day passes available.

San Diego, California

Adults-only day and hotel spa in Rancho Bernardo with gardens, whirlpools, a steam room and an 18-treatment menu, open daily 9am-6pm.

Aspen, Colorado

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

Catskills, New York

Adults-only hotel spa in Saugerties with a day pass, pool deck, sauna, hot tub and cold plunge overlooking the Esopus Creek.

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.

Taupo, Waikato

Adults-only geothermal hot springs in the Wairakei valley near Taupo, with three thermal pools fed by natural silica-rich mineral water, plus spa treatments

Auckland

A family-run rainforest resort in the Waitakere Ranges near Auckland offering a day spa, private yoga and free hiking and biking trails.

Palm Springs, California

Adults-only clothing-optional resort in Desert Hot Springs with mineral water pools, whirlpools, a nude cedar sauna and day-pass access.

Carefree, Arizona

A 20-plus-acre desert wellness resort in Carefree, Arizona, with a full spa, pools, and 100-plus weekly fitness and mindfulness classes open to day visitors by

Chicago, Illinois

Upscale day spa in Lincoln Park, Chicago, where booking any treatment unlocks all-day access to a hydrotherapy circuit, thermal suite and outdoor terrace.

Palm Beach, Florida

Indoor-outdoor luxury spa at The Breakers resort in Palm Beach, open daily 9:30 AM to 6 PM, mainly for hotel guests and club members.

Tulum, Quintana Roo

Members-only contrast-therapy spa in La Veleta, Tulum, with a dry sauna, cold plunge, hot tub and a quiet pool for adults only.

Asheville, North Carolina

Ayurvedic destination retreat in the Blue Ridge Mountains near Asheville, with day-pass spa visits and multi-night panchakarma cleanses by reservation.

Scottsdale, Arizona

Adults-only resort spa in Fountain Hills with sauna, steam room and outdoor pools, offering day passes and an amethyst facial as its signature treatment.

Calistoga, California

A clothing-optional hot springs retreat outside Calistoga with eight mineral pools, spa bodywork, and day-pass, camping, and lodging options.

Houston, Texas

A rooftop pool, cabanas, fitness center and yoga room at this Houston hotel are open to non-guests via a $60 adults-only day pass.

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.

Dallas, Texas

Hotel spa inside The Highland Dallas in Lower Greenville, Dallas, with a sauna, steam room, outdoor pool and couples treatment rooms.

Pagosa Springs, Colorado

Day-pass hot springs resort in Pagosa Springs with over 50 mineral pools fed by the Mother Spring, plus a spa for massages and body treatments.

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.