Spas with reservation required

Boutique day spa in Sedona offering massage, facials and couples treatments, with sauna, steam room and pool on site.

Adults-only hot springs resort on Miracle Hill in Desert Hot Springs with private mineral tubs, a Finnish sauna, salt room and 35 spa treatments.

A medical spa in Thornton offering Japanese head spa treatments, body wraps, chemical peels and B12 shots, with sauna, steam room and pool access.

A Houston day spa near Memorial Park offering massage, facials and spa packages, with a sauna, steam room and pool on site.

Hotel spa at the Inn at Eagle Mountain in Fountain Hills with sauna, steam room, pools and a $69 60-minute massage as its signature treatment.

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

Day spa in Cherry Hill Township near Philadelphia offering massage, head spa scalp treatments and couples sessions, open daily 9:30am to 9:30pm.

Six-room hotel spa at Hacienda del Sol in Tucson, open daily 9-6, taking both resort guests and local walk-ins for massages, facials and body treatments.

Kamalaya Koh Samui is an adults-only destination spa and wellness retreat on Laem-Set Rd with over 100 treatments, thermal circuits and multi-day health

A themed-suite day spa in Seattle's SODO district offering massages, facials, couples packages and a few overnight suites.

An adults-only wellness retreat on Ubud's Ayung River offering multi-day healing programmes, thermal circuits and plant-based cuisine by reservation only.

All-inclusive multi-night wellness retreat in Pisgah Forest, NC, combining fitness classes, spa treatments, guided hikes and farm-to-table meals in private