How lovely to come into contact with a hidden secret, and like many others, fall in love with it straight away. That is what Pierre Cardin did when he first saw the six-storey Paris house that the Duke of Morny had built in 1854. Morny, the illegitimate son of Hortense de Beauharnais, was Napoleon III’s half-brother and, after a successful career in finance, his dandy pursuits took over, which included launching Deauville as a resort. The building is on Avenue Gabriel, named for Ange-Jacques Gabriel (1698-1782), Louis XV’s architect who also created what is now Place de la Concorde. Cardin used it as a showroom as well as a home, and from him it passed to Michel Reybier, who turned it into the luxury hotel it is today.Reybier is a man of wide interests, heavily into healthcare as well as wine (his eight-bedroom villa at Cos d’Estournel can be rented, but only as a buy-out). He owns the VJ Collection, led by Hotel Victoria-Jungfrau in Interlaken, and he funded, and still partly owns, Mama Shelter, which coincidentally announced last Monday 13 March 2017, its latest property, a conversion in Prague. He has his own Réserve portfolio, in Geneva, in Ramatuelle and here in Paris. The ground-floor salons, where Cardin must have had his frocks on display, now form an interconnecting series of libraries, with walls filled ceiling-high with real books, some leather bound, some, like an Assouline of Pierre Cardin, simply too heavy for any shelf. Jacques Garcia was brought in to decorate. He turned the basement wellness area, which has a considerable pool, into a red-lacquered retreat, its reception area highlighted by a pair of gold elephants, with howdahs on their backs. There is a splendid 24/7 Technogym here, and a three-cabin spa, with Nescens products, as used by Professor Jacques Proust at the Genolier Clinic for the Prevention of Ageing – I had a divine back massage that, thanks to soft piano music (other spas, please note) seemed to soothe away all the knots and pains. And then I went back up by 73 purple carpeted stairs from the lobby to my gorgeous suite overlooking Théâtre de Guignol des Champs-Elysées, Laurent restaurant and the Eiffel Tower. It was all typical Garcia: rich damasks, in shades of deep gold and dark chocolate, with a grey-flecked white marble bathroom, and two washrooms, with Toto washlets, their doors hidden behind damask wallpaper.All evening-long there are locals in the salons, the cigar room, the bar and the brasserie. At two-Michelin-star dinner in Le Gabriel chef Jérôme Banctel offers a set menu but we went à la carte, which included Norwegian salmon confit with miso, black radish and organic avocado, and green Provence asparagus with wasabi pistou and lemon zest cream. The best-selling dessert, by the way, is a hilarious six-inch-long coffee bean, formed of chocolate-dusted meringue and filled with birch syrup ice-cream. I had breakfast in the brasserie, à la carte only, with bircher muesli amuse bouche and choices that include a healthy avocado with gomasio, whole sesame seeds, roasted in hemp, with lemon, and Okinawa oils 3, 6, 9 to recover one’s omega balance (instead, they brought me a toast tasting, multi-grain rolls and gluten-free).I smiled a lot at this luxury hotel, particularly when we toasted the owner of our Michel Reybier Goulée by Cos d’Estournel 2013 wine, in glasses – Riedel, of course.Mary Gostelow travels over 300 days a year, doing one-night stands in top hotels around the world.