If, at breakfast, one is fed silkily scrambled eggs, two squares of multigrain toast, twin wedges of Comté, and the best cappuccino outside of the finer cafés of Milan, almost anything is possible.

Those traveling in a group should consider Villa W, the hotel’s private residence with three bedrooms and butler service.

Why not bound up six flights of stairs? How about a freestyle swim against the heady currents of the Mediterranean? Or perhaps spend a day hiking up the craggy coastline of La Croix-Valmer? This is life at Lily of the Valley, a new hotel in the South of France.

It’s about a 30-minute drive from downtown St. Tropez, and yet a world away from the Riviera’s flash and glitz. It’s owned by 29-year-old Parisian Lucie Weill (daughter of French telecom magnate Alain Weill), and in many ways it’s the sort of project that only a highly attuned millennial could devise. Striking architecture and design, delicious food, science-backed fitness, cutting-edge spa treatments—taken all together, it makes for a transportive vacation. (And it’s all highly Instagrammable!)

Above, rooms for reclining; below, Villa W’s Mondrian-esque lap pool.

The 44-room hotel, flanked by two pools and a 20,000-square-foot Shape Club, was designed by Philippe Starck. His design was inspired by Provence’s abbeys, coupled with the laid-back attitude of a California ranch and finished with flora that nods to the Hanging Gardens of Babylon.

The guest rooms are smartly furnished in neutral colors and with natural materials. (Teak furnishings, sheepskin throws, and terra-cotta pottery finished the occasional piece of abstract art.) In true millennial form, they are also outfitted with the tech required to transform a glass-walled retreat into a blacked-out sleeping chamber with the flick of a bedside switch.

Repose and relax.

The wellness experience at Lily of the Valley can go both ways. The laissez-faire approach optimizes the hotel’s two restaurants. The Vista, which overlooks both an 80-foot infinity pool and the sprawling sea beneath it, specializes in Mediterranean cuisine cooked with panache by chef Vincent Maillard, a protegé of Alain Ducasse’s. The more casual, crowd-pleasing Beach Club, located on a sandy stretch of the three-mile-long Plage de Gigaro, can be accessed by either foot or chauffeured golf cart. There are thin-crust pizzas, hand-rolled pastas, French fries, croques of all persuasions, and, because this is the South of France, magnums of Peyrassol rosé.

Striking architecture and design, delicious food, science-backed fitness, and cutting-edge spa treatments.

Those in search of weight loss—and, yes, there will be a scale involved—will be following “le Programme.” Over a duration of 4, 7, 10, or 14 days, this regime includes fitness classes such as Longe-Côte, a guided lunge through waist-deep ocean water, and Crazy Stairs, a high-intensity-interval-training session that makes use of the hotel’s various elevations. For those concerned about cardiac arrest, there’s yoga, Pilates, personal training, and quality time with a rowing machine.

Cold hors d’oeuvres and a hot, hot sauna.

Spa sessions are mandatory. In addition to skin analysis and treatments from Biologique Recherche, the Shape Club offers a cryotherapy, Indiba Detox, which uses a warming radio-frequency wand to stimulate lymphatic drainage, and massage.

Le Programme followers must also relinquish control of the menu in favor of dishes devised by nutritionist Jacques Fricker. As the French tend to do, Fricker prioritizes the pleasure of eating (hence the scrambled eggs and Comté). Lunch and dinner include nutrient-rich dishes such as grilled sea bass with ratatouille, chickpea crêpes, and even tranches of steak the size of an American Express card. At dinner, one glass of red wine is permitted; otherwise, alcohol is verboten. But a modest portion of dessert that involves something superfood-y like açaí and cacao nibs will be relished. Fricker keeps portions, sauces, and oils modest, and aside from those two small squares of toast, a carbohydrate sighting is rare.

Outdoors for shut-ins.

Officially, the daily caloric intake hovers around 1,000, although those estimates struck at least this reporter as a bit low. Still, after four days on le Programme, I headed for the Nice airport well rested, clearheaded, and four pounds lighter in my carry-on, if you get my drift. I only wished I had left the property to see more of St. Tropez and its environs; it’s a bit of a shame to come all this way without witnessing at least some of the scene.

The most striking aftershocks of this holiday were the Fricker-inspired dietary changes (more protein, mostly) that seemed to stick. Two months later, those four pounds turned into eight. And until I can get back to Lily of the Valley, I’ll be having eggs and Comté for breakfast.

The writer visited Lily of the Valley in November 2022 as a guest of the hotel. Rates start at $585 per night, while a four-day “le Programme” stay begins at $2,500

Ashley Baker is a Deputy Editor for Air Mail