Spas with overnight stay

Florence, Tuscany

A 650-square-meter spa inside a 14th-century Florence monastery, with thermal pool, guesthouse rooms, bistro and day-pass access.

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

New York City, New York

Korean-style day spa in Edgewater, NJ, with saunas, thermal pools and an infinity pool, open daily 9am–9:30pm, day passes for walk-ins.

New York City, New York

Korean jjimjilbang-style spa in Manhattan with saunas, steam room, soaking tub and body scrubs, open daily 8am-11:30pm on a day-pass basis.

Ginzan Onsen, Yamagata

A riverside hotel spa in Ginzan Onsen with a thermal bathing pool, overnight stay and day-pass access for non-guests.

Seattle, Washington

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

Hudson Valley, New York

Day spa near Wallkill and Gardiner in the Hudson Valley offering massage, skincare and energy-healing treatments, with an on-site bed and breakfast for

Kurokawa Onsen, Kumamoto

Okunoyu is a ryokan onsen in Kurokawa Onsen, Kumamoto, with outdoor thermal baths open to day visitors and overnight guests, daily 8:30am–8:30pm.

San Diego, California

A resort spa on a 44-acre Mission Bay island in San Diego, open to hotel guests, with sauna, steam room and pool access.

Kurokawa Onsen, Kumamoto

A nine-room ryokan in Kurokawa Onsen where every detached suite has its own source-fed open-air bath, open to overnight guests only.

Shibu Onsen, Nagano

A ryokan in Shibu Onsen with indoor and outdoor hot-spring baths fed by two blended mineral springs, open only to overnight guests.

Ibusuki, Kagoshima

A ryokan-style hotel in Ibusuki with source hot-spring baths, both shared and private, open only to overnight guests.

Ramona, California

A vacation-rental resort in Ramona whose day-spa access, sauna, steam room and heated pool are reserved for guests staying on the property.

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.

San Diego, California

Hotel spa on Shelter Island in San Diego with sauna, steam room, and pool, open to guests staying at Kona Kai Resort.

Scottsdale, Arizona

A hotel spa at the 65-acre Fairmont Scottsdale Princess resort in North Scottsdale, open to overnight guests with sauna, steam room and pool access.

Atami, Shizuoka

A hotel spa in Atami with a thermal onsen pool, open only to overnight guests staying at Fufu Atami.

Yufuin, Oita

A small hillside ryokan near Yufuin's town center where every room has its own half-open-air bath filled with 100% source hot-spring water and a view of Mt.