Spas with hot tub

Koh Phangan, Surat Thani

Day spa in Ban Tai, Koh Phangan, with massages, baths and multi-hour packages for solo guests or couples, plus private suites and a sauna.

Orlando, Florida

Hotel spa at the Rosen Centre on International Drive in Orlando, offering massages, facials, nail care and access to a steam room, pool and fitness center.

Cotswolds, England

A wood-fired riverside sauna at Whichford Mill in the Cotswolds, with a cold-plunge bath, river dipping, and both private and communal sessions.

Transylvania County, North Carolina

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

Kapaau, Hawaii

An oceanfront eco-boutique hotel and wellness retreat on Hawaii Island's North Kohala coast, open to overnight guests only, not day visitors.

San Francisco, California

A San Mateo day spa with a hot tub, open daily 10am-9pm, taking both walk-ins and reservations for couples or solo visits.

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.

New York City, New York

A small Japanese-style bathhouse near Union Square with sauna, hot-tub onsen, cold plunge and a recovery lounge, open by reservation only.

Kyle, Texas

A 88-acre Hill Country resort near Kyle and Wimberley with overnight rooms, a garden spa, pool, hot tubs and day-pass access by reservation.

Asheville, North Carolina

An overnight-stay forest retreat near Fairview with private cedar hot tubs and a shared sauna pavilion session, not a drop-in day spa.

Philadelphia, Pennsylvania

A private-reservation spa in Philadelphia's Manayunk neighborhood for date nights, birthday and bachelorette parties, with hot tub, sauna and massage chairs