Spas with thermal pool

Philadelphia, Pennsylvania

A hotel spa inside the Four Seasons Comcast Center tower in Center City Philadelphia, open to overnight guests with an infinity pool and skyline views.

Palm Beach, Florida

Oceanfront resort spa at the Four Seasons Palm Beach, open to hotel guests only, with thermal pool, relaxation lounge and ocean-view pool deck.

Big Island, Hawaii

A hotel spa at Hilton Waikoloa Village on Hawaii's Big Island, with a pool and thermal pool, open to hotel guests.

Scottsdale, Arizona

A resort spa at JW Marriott Phoenix Desert Ridge with a thermal pool, relaxation lounge and on-site café, open to hotel guests and day-pass visitors.

West Bay, Bay Islands Department

A beachfront resort spa on Roatán's West Bay Beach with a hydrotherapy circuit, thermal pool and ocean views, open only to hotel guests.

Austin, Texas

A lakeside resort spa on Lake Travis in Lakeway, Texas, with pools, outdoor baths and treatments, open only to hotel guests.

Calistoga, California

MoonAcre Spa & Baths is a day spa in Calistoga with a thermal pool, hot tub and sauna, open daily 9am–5pm and geared toward families and couples.

Ranong

A budget thermal-bath spot in Ranong with a soaking pool and an on-site café, open daily 9am to 10pm, walk-ins welcome.

Bad Blumau, Styria

Rogner Bad Blumau is a Hundertwasser-designed thermal resort in Styria with geothermal pools, outdoor baths and hotel-guest-only access.

Palm Springs, California

A hotel-guests-only desert resort in Desert Hot Springs built around natural mineral hot spring pools, with spa treatments and overnight stays.

Taos, New Mexico

A moderate-priced day spa at Taos Ski Valley with a heated pool, hot tubs, steam rooms and a day pass open to non-hotel guests.