Chuan Body + Soul at The Langham

You can reach the Chuan Body + Soul Spa directly through a doorway at the back of the Langham Hotel. But we found it far more pleasant to go through the hotel's grand entrance, into the luxurious white marble lobby and follow the signs that take you through a warren of hotel corridors.

Inside, the Chuan Spa, like the hotel, has a fondness for Art Deco glamour, but with a modern twist. Its most striking feature is a dramatic sapphire-blue 16-metre swimming pool set in a former bank vault. How apt.

The spa reception area has muted greens, cream marble floors and Deco touches, such as the arched, lit mirror behind the desk, and antique wall lamps. Sit on a jade-coloured armchair and fill out your consultation form, then staff will give you a tour of the small but elegant spa.

The changing rooms are industrial chic with exposed chrome pipes, grey tiled floors and white tiles in the three showers. Marble sinks and vanity units, large oval mirrors and Deco lights add a touch of chic to an otherwise functional space. The Dyson hairdryers, Kirsten Florian cleanser and Chuan products in the showers made us feel like five-star guests. Towels and robes were soft and plush.

Within the changing rooms, to the rear, is a small sauna that could seat two or three, and an aroma steam room with a long, curved marble bench and room for six. The sauna had reached 90 degrees when we were there. Cool off in one of three showers, or take time to rest and sip water on an orange leather bench just outside.

There is no relaxation room, but a stylish spa lounge. One glass wall displays the newly refurbished gym; if you relax on the teal-blue velvet sofa, you can turn your back on the activity within. A glass backed shelf is lavishly stocked with teas, a coffee machine, silver mesh bowls of fresh fruit, glass urns full of water infused with either cucumber or orange, and lots of hardback books celebrating design, lifestyle and well-being: the holy trinity of the Chuan spa.

The highlight is the 16-metre swimming pool which you first glimpse from a curved steel staircase that juts over the gleaming blue-lit water below. The double height walls are lined in grey slate, a strong backdrop to the large, dangling chandelier:  a splash of glamour in an otherwise Zen-like space. The mosaic tiled pool is rectangular, narrow (two swimmers is enough, three at a push) and almost entirely fills the floor area, save a ledge with four wicker chairs at one end. Swim in silky blue waters to the glowing bonsai tree mural at the far end.

Chuan Body + Soul offers a spa menu steeped in Traditional Chinese Medicine; its philosophy is that we are made of five elements: water, wood, metal, fire and earth. It also offers treatments by Kerstin Florian and Germaine de Capuccini.

We were booked in for a Chuan Body Elements ritual (90 minutes, from £160), which finishes with a Kirstin Florian facial. On arrival, as well as the usual consultation form, we filled out a multiple choice on favourite seasons, foods, and emotions to determine which of our five elements needed rebalancing.

My therapist, Celine, led me to a large, softly lit treatment room. She told me my element today was water, which apparently relates to kidneys, bones, hair and hearing. The emotion, she said, was fear, the colour black and season winter. It all sounded rather ominous. Celine then invited me to hold the "Water" card against my kidneys on my lower back and take a deep breath. As I breathed out, I was to hum "Yoooooouuuuuu". I tried not to laugh, although it wasn't easy. We repeated the ritual three times.

I then got myself onto the wonderfully warm treatment bed, lying on my back. Celine began by washing my feet, then massaged my décolletage and neck with the warm, slightly spicy water oil. I was happy for her to massage my stomach, which felt comforting. She massaged my arms and legs, with long flowing movements interspersed with focused pressing. Occasionally, she would spray a fine hydrating mist over my body.

I turned over, and Celine knocked through the towel gently along the back of my body. She massaged my back, with short sliding strokes, sometimes using the heels of her palms and forearms for deeper penetration. It felt heavenly, especially on my sore, tense shoulder blades. As she worked the backs of my legs, I started to drift off, but was brought back into the room to turn around for the facial.

Celine cocooned me in warm towels, and after cleansing, applied a cooling enzyme peel which she allowed to set for a moment, then removed with hot towels. Next, she pasted on a soothing gel mask as my skin was quite sensitive. As it set, she gave me a gentle head massage, and finished with a serum, moisturiser and lip gel.

At the end, all my tension had evaporated and my skin -- body and face -- was gleaming with health. I wonder if my soul was, too...

Although there is a good selection of teas, nuts and fruit in the spa, you need to dress (elegantly) and head to the hotel for lunch or tea.

We enjoyed an afternoon tea in the Palm Court, which has been serving "Tiffin" for 150 years. The enormous room is dominated by spectacular fringed Deco chandeliers and gold-relief wall murals, with a black marble floor. Traditional sandwiches arrived on Wedgwood rose plates alongside a delicious Langham-blend tea that needed no milk. This was followed by cream cakes and the lightest scones, and accompanied by tunes on the Grand Piano.

You can also have lunch at the chic Artesian bar (named after a 360-foot well deep under the hotel) which serves creative bar food and cocktails. In the evening, go upmarket at Roux at the Landau.

We loved:

The spectacular pool: It's the main reason we will never forget our visit to Chuan Body + Soul.

The occasional rumble of tube trains: So London.

Our treatment: Wonderfully delivered, deeply nurturing and a little bit different.

We didn't love:

The relaxation area was not particularly relaxing. It's hard to balance your body and soul when watched by someone on a treadmill.

Getting to the spa is a bit of a faff if you're staying in the hotel; there are several corridors and lifts to negotiate.

BBC Execs: Broadcasting House is just over the road.

Visiting film stars: Chuan Body + Soul offers Zen with a dash of glamour plus discretion. The hotel is a celeb favourite.

Stressed Londoners needing to rebalance in style.

We awarded Chuan Body + Soul a Good Spa Guide Bubble Rating of 4 bubbles. It's a beautiful, luxurious and exclusive spa in a famously glamorous five-star hotel. Treatments are expertly delivered, and exquisitely thought-out, and the stunning swimming pool makes it extra special. A relaxation room would elevate this spa yet further.  

Savant Spy visited in October 2017 and awarded it 4 Bubbles.