Sunday, July 13th, Noboribetsu, Japan

An onsen is a natural hot spring in Japan. By law—specifically the Hot Springs Act—an onsen is defined as hot water, mineral water, or water vapor that naturally springs from underground at a temperature of at least 25°C (77°F) and contains certain minerals. The water is geothermally heated, often due to volcanic activity, though it can also come from deep underground aquifers or fossilized seawater. Japan classifies onsen waters into ten types based on mineral content: simple onsen, carbon dioxide (CO₂), bicarbonate (HCO₃), chloride (Cl), iodine-containing (added in 2014), sulfate (SO₄), iron (Fe), sulfur (S), acidic (low pH), and radon (Rn). Soaking in an onsen is one of the most special experiences in Japan, and here in Noboribetsu—one of the country's top onsen towns—you can find five of the ten types in one place. Today I spent two blissful hours hopping between various hot and cold pools, steam rooms, saunas, and both indoor and outdoor baths. Each mineral has different healing properties, from lowering blood pressure to softening the skin to helping with chronic conditions. Personally, I love the sulfur springs—milky white in color, with a strange smell—and said to help with hardening of the arteries and chronic dermatitis. Mineral baths and sauna rituals have become some of my favorite health and wellness practices, and it all started here in Japan about a year and a half ago. Since then, I've explored incredible facilities in Korea, Iceland, Georgia, Laos, Cambodia, China, Hungary, and even a Russian-style banya in Dallas. I like to think I'm on the path to becoming an international sauna and bathhouse expert, though I still need to visit Finland—the birthplace of sauna culture—before I can truly be certified. In Japan, men and women bathe separately in onsens. As always, you remove your shoes before entering, store your belongings in a locker, and keep the key on your wrist. Then you strip naked. Usually, you are hit with a bunch of 60+ year old Japanese uncircumcised penises all around you. Everyone is totally comfortable. At first, it's a little weird, but after a few times, it becomes freeing. Before entering any bath, you need to wash yourself—there are small stools lined up in front of mirrors with hand-held showerheads, soap, shampoo, conditioner, and a bucket for rinsing. Once clean, you're free to soak and explore. I like to alternate between hot and cold pools, do a sauna session, then cold plunge and chill outside with some tea. Today's onsen had a sulfur waterfall that poured directly over your head, which felt both healing and mind-opening. There were ultrasonic jacuzzis, full-body reclining tubs, and beautiful minimalist design throughout—clean wooden interiors, soft lighting, and peaceful vibes. Inside the sauna, you'll find tiered benches for different heat levels. I always pay attention to the details: Is the heat electric or wood-fired? What kind of thermometer is used? Is the timer a clock or an hourglass? Can guests pour water on the coals or is it automated? These things matter. Someday, I'd love to bring a thoughtfully designed sauna and onsen-style experience to the U.S.—inspired by everything I've learned from these global traditions.