Spas with ocean or lake view

Seattle, Washington

A private floating bathhouse on Seattle's Lake Union, booked out entirely for one group of up to 12 for sauna, cold plunge and hot tub rounds.

Reykjavik, Capital Region

Eight oceanfront geothermal pools in Hvalfjörður, 45 minutes from Reykjavík, plus steam baths, a bistro and guest houses for rent.

Ischia, Campania

Family-run thermal pool park on Ischia's Maronti beach, open since 1973, with three sulfur-water pools, a sauna and direct beach access.

Saint-Malo, Brittany

A seafront thalassotherapy center in Saint-Malo with an Aquatonic seawater pool circuit, day passes, and multi-day cure packages in a Belle-Époque building.

Sopot, Pomerania

A medical resort spa in Sopot built around local brine and mud treatments, open to hotel guests by reservation rather than day visitors.

Húsavík, Northeastern Region

Geothermal seawater baths built into the cliffs above Skjálfandi bay in Húsavík, with walk-in day passes and views toward the Arctic horizon.