Paris has always understood the power of ritual. Of lingering. Of making beauty something you live inside rather than simply apply. And now, on rue Saint-Honore, one of the city’s most mythologised addresses has quietly deepened that philosophy. To mark its 30th anniversary, Hotel Costes has unveiled the largest Augustinus Bader spa in the world – a 1,000-square-metre sanctuary that feels less like a hotel amenity and more like a private Parisian secret whispered between insiders.
Tucked beneath the legendary hotel, the Augustinus Bader Spa at Costes brings together two cult worlds: the brand’s uncompromising scientific approach to skin regeneration, and Costes’ unmistakable atmosphere of intimacy, discretion and seduction. It is not a collision so much as a careful choreography — one that brings cellular technology into candlelit corridors and softens clinical precision with velvet shadows and soundtracked stillness.
Designed by Studio Liaigre, the space is an exercise in luxurious restraint. Smoked oak, platinum travertine, statuary marble and emerald glass mosaic set a palette that feels both grounding and quietly decadent. Lighting designer Arnold Chan casts a flattering, almost cinematic glow throughout, while the hotel’s signature music and olfactory blends – both exclusive Costes creations – anchor the spa firmly within its Parisian context. This is not a white, sterile temple of wellness. It is warm, enveloping, unmistakably Costes.
At the heart of the experience is Augustinus Bader’s belief that skin should be understood before it is treated. Every guest begins with a 30-minute in-depth skin diagnosis in a dedicated analysis room, using advanced 3D imaging and AI-assisted measurements to assess everything from hydration to elasticity. From there, treatments unfold entirely à la carte, tailored not just to concerns but to the skin’s underlying biological needs.
The menu spans elegantly efficient 30-minute rituals – think youth-boosting hand or eye treatments – through to indulgent, two-hour immersions. The pinnacle is the Signature AB, a complete face and body ritual that integrates all of the brand’s proprietary technologies, including its famed TFC8 Trigger Factor Complex, designed to support cellular communication and regeneration. The effect is not simply cosmetic; it is deeply restorative, leaving skin energised and the body recalibrated.
The spa seamlessly embeds technology throughout. Ionix Light therapy combines LED, microcurrent and ultrasound to firm, tone and oxygenate the skin. Raja Medical microdermabrasion enhances radiance treatments, while a radiofrequency hand ritual – exclusive to this spa – delivers immediate smoothing and firmness. Even Pilates has a place here, with a dedicated reformer studio designed for guests who like their wellness sculpted and precise.
Yet for all its innovation, the spa never loses sight of touch. Massage techniques focus on activating the fascia – the connective tissue where vital cellular exchanges occur – creating results that feel structural rather than superficial. It is beauty approached as architecture, not ornament.
That philosophy is amplified this season through an exclusive residency with expert facialist Alessandro Cirino. From January 15 to February 26, Cirino brings his highly sought-after Rejuvenating Sculpting Facial to Costes, offering appointments every Tuesday and Thursday. Known for his anatomy-driven, myofascial techniques and intra-oral massage, Cirino works with the facial musculature itself, enhancing structure and symmetry rather than simply smoothing the surface.
His 75-minute treatment combines this deeply technical manual work with Augustinus Bader’s TFC8 formulations and the Lyma Laser Pro, resulting in visible sculpting, refined contours and a sense of lift that feels organic rather than forced. It is the kind of facial that editors whisper about and book months in advance – now made even more potent within the context of Bader’s regenerative science.
Beyond the treatment rooms, the spa reveals another jewel: the Pool Lounge, described by those in the know as Costes’ best-kept secret. Open daily from morning until midnight, the space invites guests to linger, offering a rare sense of unhurried luxury — a place to drift, decompress and extend the ritual long after the last serum has been pressed into skin.
As with everything at Costes, discretion reigns. There is no performative wellness here, no overt branding or clinical coldness. Instead, the Augustinus Bader Spa naturally extends the hotel’s legacy, treats beauty as both science and sensibility, and regenerates quietly and impeccably behind closed doors.
In a city that has seen every trend come and go, this is a reminder that true luxury lies in depth, detail and devotion to craft. Paris wouldn’t have it any other way.