At eight a.m. on Sunday morning, Il Pellicano was crickets. On the grass tennis court, the pros rallied with one another. In the gym, little boxes of water began to sweat. All around this verdant peninsula on Italy’s Tuscan coast, the swifts chirped ecstatically, as if broadcasting the news: Breakfast cakes are warm! Checkout’s at noon!

But the hotel’s guests could not be roused. The previous evening, Marie-Louise Sciò had a party: dinner and dancing to celebrate the Pelli’s 60th anniversary. There was a buffet straight out of the Salvador Dalí cookbook—green peas suspended in gelatin, towers of artfully draped prosciutto, and a pyramid of tiny clams, which managed to retain their brine.

Robert Rabensteiner, Sciò, and Haider Ackermann.

All sorts of beasts were sliced and diced by Italians of a certain age in white dinner jackets, wielding their long, silver knives on command. Two hundred people in finery from tuxedos to sarongs swanned about, holding a Pall Mall in one hand and a Negroni Sbagliato in the other.

Then and now: the 60s spirit of Il Pellicano lives on.

The Pelli has a mixed reputation. Despite this sort of excess, at its core it’s a place of restraint. Every espresso machine is hand-polished to a mirrored sheen, every housekeeper wishes you a buongiorno and cedes right-of-way, every knob of mozzarella is pulled by human hands.

These kinds of things just don’t happen without a general at the top. And that would be Sciò, the C.E.O. and creative director of the Pellicano Hotels Group, who, on this night, was wearing a butter-colored asymmetrical tunic that left one of her legs exposed. “Let me introduce you to my thigh,” she said, striking a pose.

Clockwise from top left: Angela and Margherita Missoni; Sciò (in Haider Ackermann for Tom Ford); Laura Brown and J. J. Martin; Gucci Westman and David Neville; Alex Eagle and Gioia Bini; Dree Hemingway.

To call Sciò a hotelier is an oversimplification, perhaps even an offensive one. She’s also an architect, an interior designer, a creator of clothing and curiosities, a marketing guru, an amateur D.J., a social-media influencer, a part-time editor, and, yes, one of the best hoteliers in the business. With these cottages on the edge of the Tyrrhenian Sea, she’s created a diamond as big as the Ritz.

But she’s really in the business of world creation. And at the Pelli, she cultivates a crowd that wealthy vacationers from all over will pay anything to observe. Who else could pull together Taylor Swift’s producer (Jack Antonoff), the world’s best-looking equestrienne (Edie Campbell), the new designer of Tom Ford (Haider Ackermann), the founder of A.P.C. (Jean Touitou), a top beauty innovator (Gucci Westman), a Wimbledon champ (Maria Sharapova), and three members of the Missoni family? She even convinced some of them to wear Speedos. (The Pellicano teamed up with the brand, along with Highsnobiety, on a new collection. And it’s kind of great.)

Miriam Leone, the actress and former Miss Italia.

On Saturday night, after the feast, many danced themselves ragged. At some point, pizza was served on silver trays. By four a.m., the D.J. had sputtered out.

The beach known round the Internet.

But peace was short-lived. At lunchtime on Sunday, the espresso machine was whistling nonstop as the beautiful people returned to the breakfast room. “I hope we don’t have to wait another 60 years to do this again,” said one sad-eyed Englishman, drinking a cortado before leaving for Fiumicino. Sorry, honey. Some things only happen once in a lifetime.

Ashley Baker is a Deputy Editor at Air Mail and a co-host of the Morning Meeting podcast