USP Jet-set. Nestling just behind Monte Carlo casino is one of the Riviera’s most exclusive and well-established spas, Les Thermes de Marins. The spa caters to the health and fitness needs of long-standing Monaco residents, as well as those of the many visitors that pass through this tiny principality. It is affiliated to several of the principality's major hotels (in fact, it connects with one of the hotels via an underground tunnel) and welcomes day visitors.

AMBIENCE Old-style Riviera glamour. The spa is spread over four large floors and houses everything from hairdressers and gyms to beauty salons and therapy rooms. Here you can try the latest cellulite-removal techniques - a problem the French and Monegasques pay particular attention to - to ensure that your body is fit for life on the Cote d’Azur. Despite its prices it is not an intimidating place to be and you can take your time there. The large terrace overlooks the main port, and as you lie back on one of the sun-loungers, looking at the stunning yachts in the deep-blue Mediterranean sea it is hard not to feel seduced by the Monte Carlo way of life.

EXPERIENCE The staff is suitably cool and discreet, and sunglasses and logos are de rigueur for guests. Upon arrival you check in for your treatment, paying upfront. There's an extra day charge for access to the swimming pool, Hamman and sauna. As well as a day visitor’s pass, I had booked an hour-long bespoke massage - a hard choice from the dozens available promising all sorts of results. I plumped for a straightforward relaxation massage which left me feeling very calm and true to its description, relaxed. My masseuse spoke English, though a friend who had a similar treatment told me that she struggled to communicate her shoulder problem, so if you don’t speak French it might be worth checking in advance so you can request an English-speaker.

IN CROWD The spa is far too secretive to reveal who goes there but one imagines it's a frequent pitstop for famous Formula One residents and Le beau-monde. Monegasques mix comfortably with foreigners, mainly from Russia, Britain and Italy. Even in high-season, the size of the spa means that it never feels crowded. It is a great place to people-watch as Italians in their towelling dressing gowns and sunglasses chatter into their mobile telephones, wandering among the elegant French women d’un certain age and the younger women from Russia who preen and pamper themselves in preparation for a night at the Casino.

FOOD As well as a café, there is a more formal restaurant, which offers two menus, one to cater for a healthy appetite and one for those who are following a strict calorie-controlled diet. The food is great and you can feel full and virtuous, slim of body and most certainly slim of wallet (at this point it is best to have stopped adding up how much you are spending).

WALLET WATCH Unless you happen to be staying at one of the hotels that partner with the spa to give guests free access to the pool and gym, you need a sizeable wallet even to step in the door. It is possible to sample some of the Riviera lifestyle without breaking the bank if you know what to ask for. To my mind one of the best-value packages on offer is the Combination of Four Marine treatments – this allows you to choose from four of the water-based relaxation treatments plus access to the pool, sauna etc all for €140 (£90). Perhaps in anticipation of an influx of male business travellers, the spa, has introduced a men-only programme "Exclusive Homme" to de-stress and energise the body, with a 105-minute treatment costing €175.

NEED TO KNOW Le Thermes Marin Monte-Carlo (00 377 92 16 49 46; www.montecarlospa.com)

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