If you’d like to fly to the moon but don’t want to spend your valuable time with Elon Musk or Jeff Bezos, may I suggest a trip to the Blue Lagoon in Iceland? The landscape is almost as strange and unearthly, with fields of lava rocks—some deep-black, some covered in moss—curvy pools of pale-blue water, and not a tree in sight. The flight from New York City is only five and a half hours. (It’s about three from London.) And your skin will be so much happier.

I landed in Reykjavík after a few days in the lushness of Ischia. Could anything be more different? I had to blink over and over to adjust my eyes to the terrain. My driver told me cheerfully that the road we traveled from the airport to the lagoon had been covered in lava from an eruption a few months earlier. “How long did it take to build a new road?,” I asked him. “Oh, about a day.” The lava rocks were piled up like a medieval wall, in part to protect the lagoon and its hotels.

A large section of the lagoon is a busy tourist hub, with bused-in crowds pushing through turnstiles before they submerge into the steamy waters. On the other side is the Retreat, an austerely elegant hotel and spa so quiet that you’ll find yourself whispering. The only sound is the groan and creak of water being pumped from the depths of the earth.

That blue water is the star of the show. The Retreat’s architects arranged the hotel for maximum exposure to the dramatic setting, with enormous windows framing the pools and lava fields, the drifting steam providing the only clue that you aren’t looking at a painting.

The guest rooms have the minimalist luxury that seems to be the hotel’s credo. Everything is black, white, gray, and brown wood, comfortable but not indulgently so. One wall is given to a floor-to-ceiling window. There’s a big, freestanding tub arranged to take in the view, and a shower with buttons that create a pulsing massage. The narrow terrace is just the right perch from which to view the northern lights.

I started my first day with a yoga class, filled a bowl with Icelandic yogurt and berries from the breakfast buffet, then shuffled down to the spa in my bathing suit, robe, and slippers.

Those irresistible 100-degree waters are almost thick with minerals and microalgae. And the rumors about their healing properties are backed up by decades of scientific studies. The lagoon’s skin-care benefits were discovered by accident in the late 70s, when workers at the nearby geothermal plant dug a pit and bathed in it at the end of the day. One Icelander told me they’ll pop into any body of heated water. Some of the workers who happened to have psoriasis or other ailments found their skin clearing over time. As soon as the local doctors heard that, they, too, flocked lagoon-ward.

Sky-high: the northern lights as seen from the Blue Lagoon.

After investigating the waters, scientists enlisted by the Blue Lagoon isolated the silica and other minerals to create a skin-care line. They also found a way to encapsulate the silica and microalgae to mimic the skin-cell membrane, allowing the ingredients to penetrate deep beneath the surface. How many times have you heard that claim from a serum or cream? My estimate: a zillion. “The skin-care business is sort of the Wild, Wild West,” says Dr. Ása Bryndís Guðmundsdóttir, the lead research-and-development scientist at Blue Lagoon Iceland. “You can claim anything and say anything.”

But the Icelandic scientists published more than 20 scientific papers in peer-reviewed journals to verify the Blue Lagoon’s claims. Once this combination of elements penetrates the epidermis, it “induces our skin cells to produce proteins that are integral for the structure of the skin’s barrier.” The result is the BL+ skin-care line, which, she says, creates “more collagen-dense skin,” a stronger skin barrier, and, as she’s not one to exaggerate, “slightly better wrinkles.” I’ll take it.

I meander through the pools, imagining my skin stronger and my wrinkles slightly better by the minute. A mother and her daughter drift by, their faces covered in the chalky mask. Couples bob around holding glasses of Chardonnay. In one pool I join a lineup of bodies on floating mats. We’re covered with wet blankets while we’re massaged and dunked in the warm water, over and over. I wander into the spa’s grottos for its skin ritual, scrubbing my body with pure lagoon salt (because it’s filtered through lava, it’s free of microplastics), basting with silica, and, finally, coating myself with algae, rinsing off between each layer until I feel purified. I finish with a round of sauna, steam, and cold plunge in a waterlogged stupor.

At dinner at the Retreat’s Michelin-starred restaurant, Moss, I change my mind about the tedium of tasting menus. This one is bright and unpretentious, as these things go. The vivid beet soup appeals even to my beet-averse partner. Autumn vegetables are topped with pastry shaped to look like antlers, and the coconut mousse is covered in dark chocolate to resemble a lava rock. I recognize the other diners from the spa: the young couple I shared algae with; the mother and daughter, now clear of masks; and the woman who balanced a glass of red as she dozed in a hanging chair. We’re all glowing in the soft light.

The concierge offers to ring our room if those other lights, the aurora borealis, appear, and just as we’re about to drift off, we get the call. We bundle up and climb to the roof. The sky doesn’t look like much to the naked eye, but when I hold up my iPhone camera, there they are: shots of bright green and streaks of magenta, swirling silently above us.

It’s peaceful, maybe deceptively so. The tectonic plates and the volcano have been restless lately, and the eruptions have caused the hotel to evacuate several times over the past few years. It adds an air of excitement, even danger, to the calm.

As I pack up for home, I fill my suitcase with jars of the lagoon’s salt, a trio of masks, and the BL+ serum, eye cream, and face cream, determined to become a little less wrinkled without the soothing benefits of lagoon water or the threat of the shifting earth.

The writer was a guest of the Blue Lagoon, where room rates at the Retreat start at $1,606 a night and include access to the spa and lagoon

Linda Wells is the Editor at Air Mail Look