The Soak: “No pain, no gain” is the motto at this unique beach just south of the North Island’s Mercury Bay: you have to bring a shovel and dig your own “hot tub,” which for two hours before and after low tide will fill with spring-fed water laced with calcium, magnesium, potassium, silica, and fluorine. Note: also bring a bucket to add cold seawater to regulate the temperature, which can emerge at a scalding 147°F.
The Scene: It’s a communal Kiwi beach bash, so arrive early to stake out your circle of sand.
When to Go: Year-round, but summer (December to March) is ideal.
The Soak: Known as the Sacred Pool, this divine dip in southwestern Turkey lives up to its name: as you float in spring-fed water that’s a relatively refreshing 94°F, look up at a cerulean Aegean sky and down at 2,000-year-old Greek and Roman antiquities scattered on the pool’s floor.
The Scene: The eye candy here is a panorama of gleaming white terraces—Pamukkale means “Cotton Castle” in Turkish—created as flowing water deposited layers of calcium carbonate. Soaking in these natural pools is no longer allowed, but you can snap photos and then visit the nearby Roman city of Hierapolis.
When to Go: Year-round, but early fall is particularly lovely.
The Soak: Healing power on a massive scale—literally, as its real purpose is to supply hot water and electricity to 45,000 Icelanders—this lagoon just outside Reykjavik holds 1.6 million gallons of 99°F–102°F geothermal seawater laced with silica, minerals, and algae.
The Scene: With 400,000 visitors annually, Blue Lagoon has a theme-park feel. Still, a soak here is undeniably cool, like a communal pool party of Icelanders and tourists slathering silky silica mud on their faces and bodies.
When to Go: Year-round, but Iceland’s winters are notoriously glum with just a few hours of daylight, while summers are 24/7 celebrations since the sun barely sets.
Guana Island, BVI
If escaping somewhere far from the madding crowd is your idea of heaven, this privately owned isle in the British Virgin Islands will render you starry-eyed. With just 20 all-inclusive rooms, a maximum of 32 guests, and no other island inhabitants, Guana offers blissful serenity and the chance to get back to nature (850 glorious acres worth). While children are welcome, this is a destination tailor-made for couples, with seven pristine beaches, miles of hiking trails with sublime ocean views, and perks like movies under the stars in a cliff-side setting known as the Garden of Eden. Be sure to book a massage in the “spa”—an alfresco cabana tucked discreetly in mangroves behind the main beach—where the soundtrack is the murmur of the sea and breezes rustling the palms.