Welcome to the third iteration of Vogue’s global spa guide, a compendium of the 100 best spas in the world, compiled based on first-person reviews and careful editing. This year, we’ve renewed our focus on establishments that have established a reputation for exceptional care of body and mind, though there is a great variety in the list. Whatever you are seeking when it comes to wellness, there is something here for you.

Why go here?

For Italians like me, Saturnia is a storied location. As a kid, I would bathe under the stars just below the hotel Terme di Saturnia, in the free outdoor springs of Cascate del Mulino, famous for their steaming white sulfur waters. As an adult, looking for a bit more comfort, I started visiting the hotel. I always loved the vibe: a mix of elegant and laid-back. Sometimes hotels have a kind of rigidity around “wellness.” The programs are strict; the guests are striving; everyone is a bit manic about detoxing. We overbook treatments and activities in a kind of improvement frenzy. But here, there is a timeless peacefulness: The springs are over 3,000 years old—older than any wellness philosophy.

When I arrived this time, frazzled and overburdened with normal life, the wonderful Federica Bucciotti (the hotel’s marketing manager) took my hand and asked me to take 24 hours just for myself. When was the last time anyone had asked me that? “This is a very democratic place,” Bucciotti told me, indicating that there was a home for everyone. But I discovered something not only democratic but also equalizing: Somehow, floating in millenary water, something drops and you remember that we’re all the same.

Come here when you need something that feels exceptional but also authentic.

What’s the vibe?

The first thing you notice when you arrive is that soft, unmistakable smell of sulfur. Somehow, it’s not unpleasant. In the morning, breakfast takes place overlooking the steaming pool, and the air is thick with mineral vapors; everything looks a bit blurred at the edges. From the dining room, the view alone is a prescription for instant relaxation.

In the pool, the mood is unexpectedly convivial. The main thermal spring is vast, yet it feels like a cozy living room, with groups naturally forming against the travertine edges. I met a wonderful couple that way: a yoga teacher and a designer. Within minutes we were exchanging stories as if we’d planned to meet there.

What’s the history

Locals will always start with the myth. The story goes that the Roman god Saturn, fed up with human belligerence, threw a thunderbolt that split the earth open and created a crater from which sprang miraculous, calming water. Myth aside, people have been coming here for centuries. First the Etruscans, then the Romans, who appreciated the springs for their wound-healing properties. The town of Saturnia became an important stop along the ancient Via Clodia, a strategic resting point for soldiers traveling between Rome and the ancient region of Etruria.

By the 15th century, the baths were officially recognized as a place of healing. In 1865, the Ciacci family began building up the infrastructure around the springs. The hotel you see today was built in 1919, but everything still revolves around that same water bubbling up from the earth at a steady 99 degrees.

What should you try?

Here it’s all about bathing. But what makes the experience unique—other than the water itself, rich in sulfur, carbon dioxide, bicarbonate, and minerals—is the thermal plankton, a microorganism that develops naturally in the sulfurous water and is considered a secret boon for the skin. Supposedly, it helps rebalance, soothe inflammation, and support cell turnover. You’ll see many guests spreading algae and mud on their faces while they soak.

There are several add-ons available for the basic bathing routine: skin and body products, facials and body treatments that incorporate a skin-care line derived from the thermal water and plankton, and mud therapies that use the clay matured in the same mineral water. There is now increased attention paid to what goes into treatments, and I especially enjoyed Terra and Acqua, a blend of Eastern, Ayurvedic, and Western techniques using the thermal mud and spring water to detox and relax.

Beyond that, I’d recommend a session with Laura Quinti, the on-site naturopath. Laura is not for the faint of heart: One look into my irises and she told me more about my gut microbiome than what I’d expect from a long list of tests. And she will be very straightforward about what she thinks you need. The hotel has collaborated with her for years for naturopathic consultations, bioenergetic cleansing, reiki, and crystal work. I spent 45 minutes with her and was sure I’d gone to another planet for hours. After our session, something genuinely shifted in my body. When I told Bucciotti, she wasn’t surprised. “The treatments go as deep as you’ll let them,” she said.

What else do we need to know?

Stay longer than three days, if you can. I know it’s annoying advice; everyone has a life! But it’s true. Something shifts after day three. Your nervous system accepts that you’re safe. In any case, the best move is not to cram too much into the experience: sleep, eat, and soak, in close contact with something genuinely ancient and a little magical.

Who can go?

Literally anyone. The hotel welcomes all ages, though kids under 18 generally can’t use spa facilities alone. Anyone with a day pass (not just hotel guests) can use the spa; that pass gives access to outdoor thermal pools, whirlpools, vascular paths, sauna, changing rooms, showers, and parking. You can add things like a wellness kit (bathrobe/towel), sunbed, umbrella, or flip-flops. There’s also a more exclusive “club” access option that encompasses indoor relaxation spaces and extras like reserved loungers and better facilities. You can also book treatments and programs without being a hotel resident, and combine them with day entry. Book ahead on weekends.

It’s worth noting that the hotel is also surprisingly pet-friendly. One guest had a very enthusiastic Labrador in the hall; he barked like he owned the place, and nobody batted an eye. Pets get bowls, beds in designated rooms, and there’s pet-friendly outdoor space near the springs.

Booking details for Terme di Saturnia

Address: 58014 Terme di Saturnia GR, Italy

Read more from Vogue’s Global Spa Guide.