By the end of 2028, when a third outpost is slated to open on South Bank, visitors to London will have three Mandarin Oriental hotels from which to choose. For now, there are two: one in Knightsbridge, the other in Mayfair. Geographically, there’s only a 10-minute cab journey between them. In every other way, the hotels are worlds apart.

Mandarin Oriental Hyde Park moved into a 19^th-century chateau with turrets and chimneys and an elaborate brick-and-stone façade (the Hong Kong-based hospitality group knows how to do up dilapidated old piles). Over in Mayfair, on a corner of Hanover Square, opposite the former Vogue House building, the group chose to demolish what was already there, paying Rogers Stirk Harbour + Partners a princely sum to construct a 12-storey townhouse that just about sits in harmony with the red brick and white stucco of the surrounding conservation area. Incidentally, RSH+P was the architectural firm behind another recent starry new-build hotel, The Emory in Belgravia. The practice’s accomplishments in W1 are the much greater achievement.

This prime chunk of Mayfair has history. Before Mandarin Oriental, 22 Hanover Square was home to Celanese House, the grand, Art Deco home of chemical manufacturer British Celanese – finished in 1928, following the recent discovery of Tutankhamun’s tomb, the building featured decorative Egyptian details fashionable at the time – and played host to various London Fashion Week events in the ’50s and ’60s.

Before then, an older building on the site acted as the home of the Oriental Club, whose members, we learn from 19^th-century Scottish novelist James Grant, were ‘remarkable for the quantity of snuff they take.’ (Inside a snuff box shaped like a ram’s head, Grant wrote, there were little snuff rakes and little snuff spoons. We digress.) From 1775, an even older, Georgian building sat on the site. Designed for concerts, it was known as the Hanover Square Rooms. It hosted performances by Haydn, Mendelssohn and Lind.

Today, you’re more likely to bump into rappers and C-suite execs than classical musicians at 22 Hanover Square. If the imposing lobby and acres of wood panelling at Mandarin Oriental Hyde Park make you wish you’d packed your smoking jacket and velvet slippers, its sister digs in Mayfair are as chic and sophisticated as the magazines formerly put together in the Condé Nast building across the square.  

RSH+P has split the building into two pavilion towers. Connected via a glazed stair and lift core, natural light filters into the building, all the way down to the basement restaurant. It’s a clever bit of architectural alchemy, illuminating interiors by Chelsea-based Studio Indigo, which has done a fine job accenting timber and marble and stone with subtle specks of brass, bronze and gold. The lobby is so unassuming you’re not sure you’re in it. Guests visiting ahead of September will notice works by international sculptors Seo Young-Deok, Pieter Obels, Alfred Haberpointner and Lee Gil Rae littering the hotel’s public spaces. The installations are part of an immersive art series the hotel is running with nearby Opera Gallery, which celebrates contemporary art from its home just around the corner.

If Mandarin Oriental Mayfair feels boutique, that’s because, compared to its Hyde Park sister (141 rooms) and soon-to-open South Bank brother (171 rooms) it is. The Hanover Square hotel is not really a hotel, you see, but a collection of 77 private residences (with interiors by Thomas Juul-Hansen), with 50 bedrooms attached (22 of which are suites). The upside is access to tip-top shared amenities that, for the most part, will be underused – there’s a gym, spa, sauna, steam room and the largest swimming pool in Mayfair. We were the only ones in it. Twice.

The bedroom minibar is built into the price of the room, of course. But while you’re here, it’s free. It’s a nice touch. It means you don’t have to count the cost of all those packets of sugary nuts and cans of local IPA. The wallpaper is silk and hand-painted. The flowering magnolias featured are a nod to the trees in the square outside. Toilets sense you coming, lift up their lids and prewarm their seats. Everything is serene and chic and solid and reassuringly expensive looking. What you’ll mostly remember after checking out, however, are the green marble stairs that lead from the lobby to Akira Back’s eponymous restaurant below.  

Floating down in a spiral, they form the focal point of the hotel, and provide a theatrical entrance to Back’s first UK venture, which includes a Michelin-starred chef’s table, Dosa by Akira Back, and a bouji, late-night penthouse spot, ABar Rooftop. The subterranean restaurant, which feels like a courtyard, benefits from a triple-height ceiling, making use of all that light, and features a huge sculpture of twisted wooden ribbons, seemingly caught in a vortex that can’t be felt from the tables below.

If the décor feels Scandi-Japanese, the menu leans Japanese-Californian – for reason. Back might not enjoy much of a profile over here, but he’s bigger news in the States and East Asia. Born in Korea, Back moved to Colorado as a teenager, dabbled in professional snowboarding, before cutting his teeth in top Japanese restaurants in Aspen and Austin. He now operates 28 restaurants, a sprinkling of Michelin stars between them, on four continents. Back’s international signatures include tuna pizza, Hot Mess sushi rolls, Wagyu tacos, and Jidori chicken – all present and accounted for in Mayfair. Other standouts included the raw octopus, and skewered lamb chops.

You won’t struggle for five-star hotels in this part of town. But few feel as private, personable and peaceful as the sophisticated space Mandarin Oriental has magicked out of thin air on a corner slither of Mayfair.   

Rooms from £1,000 per night, visit mandarinoriental.com.

Read more: The best five-star hotels in London