Hear it first, here on Robb Report Hong Kong: Botanic Sanctuary in Antwerp could soon be the top urban resort in the world, anywhere.

Antwerp? It’s the discreet Belgian city, just under an hour by train from Brussels. It’s best known for diamonds—or it was. Soon, Botanic Sanctuary will be top of the list. The experience starts on arrival at Antwerp’s cathedral of a station. Botanic Sanctuary’s white hybrid Porsche Cayenne awaits, with a flat-cap driver and a butler in leaf-green with golden corsage (all the team members are dressed by royal designer Édouard Vermeulen).

It’s 10 minutes to the hotel, set in the city’s Botanical Gardens, which evolved over two centuries ago. They grew medicinal herbs for the neighbouring St Elizabeth’s Hospital, part of a large medieval complex that included monasteries and convents, and a glorious church.

The holies moved out, leaving their superb buildings behind. Local developer Eric De Vocht moved in and, with his designer wife Maryse Odeurs, spent eight years minutely converting six of the former monastic buildings to what is now a 108-room Leading Hotel of the World. (The couple had already created Antwerp’s Hilton and one lesser hotel, but now they were after luxury.)

A hotel reception area that is a giant plant-filled conservatory sets the tone. This is a resort for all the senses. The deconsecrated chapel, still with breathtaking stained glass and acoustics that bring top maestros to tears, is used for organ recitals, regular concerts, and dinners for meetings.

Dotted around the whole are eight restaurants, with four Michelin stars between them. Botanic Sanctuary has cleverly persuaded the region’s top restaurateurs to move in, lock, stock, and barrel, bringing awards and regular customers with them. 80 per cent of diners, all meals, are not staying in the hotel.

Lunch at two-star Hertog Jan, for instance, might well include local white asparagus, charred on a charcoal burner and brought to your table by co-owner Joachim Boudens. He then spoons Belgian caviar on top. It’s as creamy as the caviar tart that awaits in your room—one bite of heaven.

Hotel suite 119, typically, is mostly taupe, from satin-smooth new wood floors up to centuries-old wood ceilings. Natural linen forms drapes and upholstery. There’s an electric-fired flickering fire. Copious books cover Matisse through to modern seaside cottage design.

Outside comes inside here, just as old pairs seamlessly with new. There’s an apothecary store, where 200 years ago nuns used to dispense. Today, fashionistas and others drive from far afield to stock up on natural potions and lotions including the eighth-generation St Charles, which also has dedicated boutiques in Berlin and Vienna.

One part of this mammoth Antwerp operation flows into another. Botanic Sanctuary’s German managing director, Christian Hirt, knows wedding parties often want to check out the well-labelled plants in the garden. Weekending couples go crazy when they start exploring the history of the whole. And once somebody starts exploring hangings on some walls—a jute sculpture here, Asian heads there—it’s necessary to call in Xavier Le Cerf.

This Antwerp-born passionista is spa director, plus musicologist and the Botanic Sanctuary’s art curator. His storytelling ranges from why a red-white-and-black block painting in one restaurant had to be extended to why four black heads peeping out of grass are at different heights.

But his stories stop when he’s showing off the new-build three-floor wellness centre. There’s a whole floor of latest fitness, an Olympic pool with blazing fire at one end, and the spa.

Try global diagnosis here. Being electrically connected via one’s ankles to a Vitatec global diagnostic machine at 7.30 am for a 14-minute assessment of no less than 600 sound beats in the body is a great pre-breakfast exercise. It certainly gives an appetite for Botanic Sanctuary’s popular breakfast buffet, in a room that centuries ago was a nursing ward run by monks and nuns.

Botanic Sanctuary Antwerp is serious business, from every point of view, and worth every precious minute.

All images courtesy of Botanic Sanctuary Antwerp.