Read our writer's views on this property below
London's new Bulgari has one of the city's most drool-worthy spas, Saska Graville is delighted to discover.
As befits the first luxury hotel to be built in London for 40 years, and one created by one of the world's premier luxury brands, Bulgari Hotel & Residences in Knightsbridge is a five-star experience all the way.
When the cheapest room on the rate card is £690 ($1050), soaring to £12,000 for the top suite, you'd expect nothing less than seamless gloss, polish and perfection.
Guests don't pay that sort of money for the real world to intrude in any way, shape or form. And it's safe to say, it doesn't.
In all my years of hotel reviewing, I can't think of another hotel that has so confidently exuded wealth. Not in a flash, blingy way - quite the opposite, in fact.
Don't be fooled by the buttoned-up restraint upstairs.
Bulgari is conservative to the point of being a touch staid (more on that later), but every detail, every gesture, every sensation is elegantly well-heeled. Surfaces of polished mahogany, silver and onyx gleam, plush custom-made upholstery beckons and sharp-suited staff hover to respond to their guests' every whim.
Which is where my Bulgari journey begins - with David, my butler. Escorting me to my third-floor Knightsbridge Suite (£4000 a night), he hands me his business card and walks me through my temporary home. (I'm allowed to call it that, because the personalised business cards in my room announce Bulgari as "My residence in London". A slick touch.)
That residence starts in a private hallway, before opening up into the suite itself. Already it's more roomy than my London apartment. A giant L-shaped sofa and desk fill one end of the living area, with a dining table at the other end. Wardrobes line the passage through to the bedroom (one of them a walk-in), where a bigger-than-king-size bed dominates. Double doors lead through to the bathroom, complete with a raised shower/bathing area.
It's elegant, luxurious and comfortable. It's also ever-so-slightly strait-laced.
Don't get me wrong - with its polished mahogany wall panelling, marble bathroom (filled, of course, with exquisite Bulgari toiletries) and bespoke velvet drapery, the whole suite is floor-to-ceiling elegant, but doesn't flaunt its luxury credentials.
There's none of the deco glamour that you find at the Savoy or Claridges. None of the Ritz's high-end tradition or the quirkily luxe detail that the Soho Hotel has in spades. Sleek, grown-up and sophisticated, yes.
But maybe that's the point - Bulgari is low-key and understated. It's all about quiet sophistication and hush-hush elegance. If you want drama, go elsewhere.
Yet there is breathtaking drama - you just have to know where to find it. The hotel has a secret. Five storeys below ground level is one of the most gorgeous playgrounds for grown-ups in London.
Don't be fooled by the buttoned-up restraint upstairs. Go underground and you'll find a spa that is, quite simply, a monument to all things indulgent and twinkly.
It's no surprise that as I left the office, announcing that I was en route to Bulgari, it wasn't the hotel itself that caused a green-eyed stir with colleagues, it was the spa access that my overnight stay enabled.
You want hotel personality? The spa is where you'll find 2000 square metres of it.
A 25-metre pool (the longest in a London hotel) glows with green-and-gold mosaic tiles, leading your eye to the yellow gold-leaf mosaic-tiled vitality pool shimmering at the far end of the room.
Lining the pool edges are individual wooden four-poster frames draped in gauze, and each containing a cream upholstered daybed. This is a place to linger.
I can still picture that pool vividly in my mind's eye, 48 hours on. I'd struggle to give you much detail on my Knightsbridge Suite.
And it gets better. The spa has 12 treatment rooms, including one double suite with its own steam room and jacuzzi.
In contrast to the conservative decor upstairs, these rooms ooze glamour. Slabs of shiny-green onyx clad some of the walls (it took the interior designers six years to produce the tiles so that the veins in the stones matched up) and stained-oak panels line the corridors. Elsewhere, sand-blasted Vicenza stone, complete with the imprints of tiny fossils, adds another tactile layer to the visual experience.
Fancy a workout? Elle Macpherson's trainer, James Duigan, is on hand, with his Bodyism studio. When the most famous body on the planet declares that "there is simply no one better in the world" than Duigan, you know that this is a gym with five-star credentials.
Pool, spa, gym ... the whole place is a show-stopper and has well and truly wrested the crown of "best London hotel spa" from my previous favourite, the Corinthia.
Even if a hotel night is beyond your budget's reach, beg, borrow or steal yourself some time in the Bulgari basement.
A minimum two-hour treatment is needed to gain full access to the magical setting, with prices from £220. Worth. Every. Penny.
Feeling really flush? For £700 you and a partner can enjoy three hours in the private spa suite, including a two-hour treatment of your choice. Truly a once-in-a-lifetime treat.
Maybe, in the end, it's the upstairs-downstairs contrast at Bulgari that makes the hotel special. It doesn't flash its luxury credentials, it wears them lightly, and it keeps its show-off, flamboyant side firmly hidden from public view. But I know it's there now.
Anyone want to go halves on a private spa suite?
The writer was a guest of Bulgari Hotel & Residences.
Top marks London's most magical hotel spa, with its 25-metre pool, glittering gold-leaf mosaic and treatments to die for. Exceptional.
Black mark A lack of design personality. Top-end and flawless, yes, but perhaps a little too strait-laced.
Don't miss Obviously, a dip in the hotel pool is a must. And the barman at Il Bar serves a mean cocktail. I loved the carrot and lavender Bellini, and was seriously tempted by the cherry and pistachio combination.