USP The spa is newly branded as the only Anne Semonin spa in London and is open to hotel guests and Londoners alike. Anne Semonin pioneered the tailor-made spa experience and all her practitioners are trained to adapt treatments and mix her products (all made from natural ingredients) to suit the individual. Being at the centre of London, the spa specialises in stress reduction and Anne Semonin has designed a bespoke facial especially for 51.

AMBIENCE Off a busy road between Buckingham Palace and Victoria hides a delightful little oasis: an almost Mediterranean-style 19th-century courtyard with a fountain at its centre and walls covered with bright green tiles topped with a redbrick frieze of scenes from Shakespeare’s plays. Here you will find 51 Buckingham Gate, a five-star apartment hotel (owned by India’s premier Taj group) and The Spa at 51.

The public spaces are fairly non-descript upmarket contemporary hotel, but the treatment rooms are newly refurbished candlelit calm with gentle New Age music, and an impressive array of little bottles. Staff are friendly, confident and well-informed. Use of the small gym is included in the price of a treatment as is access to the single-sex saunas and steam rooms.

QUALITY OF EXPERIENCE A brief session in the gym (where personal trainer Joe denies that my core muscles are useless, saying politely that they merely “need work”), and I am well ready to go upstairs with Sonja.

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I explain that my main problems are lower back soreness and neck/shoulder tension from working at the computer. She smiles knowingly (this is a London spa) and proceeds to apply hot towels to my feet and begin the Anti-Stress Back Therapy.

After skilfully picking out the main tension points, Sonja prepares a mix of mineral-rich marine mud and self-heating algae. As you lie back on the mud it heats up and begins to bubble, “like gentle lava” says Sonja, or a paste-on mini-Jacuzzi, I think.

While my back warms and pops, Sonja gives my legs a light lymphatic drainage massage. Anne Semonin has worked with two doctors to develop lymphatic drainage techniques, particularly (and unusually) for the face. This forms an important part of her L’Experience Signature Facial for 51 which Sonja now begins.

My skin is fairly typical “city” she says: basically normal with a few “issues” (translation: spots/blemishes) due to stress, hormones and pollution. She recommends a mix of moisturising and detox for the facial (she also has recipes for everything from acne to dilated capillaries). The main detox mask is once more algae (though not self heating this time) and is accompanied by eye treatments and gentle massage.

Sonja’s skin is perfect, I notice, and mine does feel fresher and look healthier by the time she has finished. I have certainly de-stressed too – in fact I am 80 per cent asleep and have to be revived with a shot glass of refreshing watermelon soup before I can get back to work and replacing those blissfully removed stressy toxins.

FOOD The Spa has a small breakfast room with complimentary cereals, toast and drinks for those en route to the office. The Spa Cuisine menu offers a few tasty and well-presented light meals such as paupiette of salmon and Thai wok-fried chicken that can be eaten in the Spa, the library of 51 or al fresco in the courtyard. For something more substantial, The Bistro at 51 serves modern European food, Quilon (next door) is a Michelin-starred Indian restaurant and Bank Westminster restaurant, behind a curved glass wall on the same courtyard, specialises in British food.

IN-CROWD Rub shoulders with sheikhs, Hollywood stars and dignitaries as well as day visitors from nearby offices who tend to come for treatments in their lunch hour. The Royal family previously owned the property, using it as overflow for guests visiting Buckingham Palace, so you never know...

WALLET WATCH Treatments start from £35. The 45 minute Anti-stress Back therapy costs £65 and the signature facial (90 minutes) £110. Take advantage of an exclusive 10 per cent discount for Times Online Good Spa Guide readers, on any spa treatments and retail purchased, when quoting "Times Online" (offer subject to manager's discretion).

NEED TO KNOW The Spa at 51, 51 Buckingham Gate, London SW1E 6AF (020-7963-8307; www.51-buckinghamgate.com/club)

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