Sting did not celebrate his 50th birthday in Marrakesh - even though everyone thinks he did. Yes, he had planned a much-publicised bash that included taking over the entire Amanjena Hotel at an estimated cost of £30,000 a night, but then along came September 11 and the singer decided to make alternative arrangements.

Marrakech Magic : The Djemaa el Fna Square

is a hive of activity in the evening.

Three years on, the list of star names flocking to Marrakesh to mark a special occasion or, indeed, to create a special occasion just for the sake of it, grows longer by the month. The rapper P Diddy flew in his A-list friends for a lavish party; Brad Pitt and Jennifer Aniston marked their wedding anniversary with a trip to the Berber city; and David Bowie and his model wife, Iman, frequently visit in the spring to entertain friends and family.

Marrakesh's "often in town" directory is heaving. Naomi Campbell, Kate Moss, Oliver Stone, Tom Cruise, Jeremy Irons, Demi Moore, Elton John and Thierry Henry are all regulars, following hard on the celebrity footsteps of past icons such as James Stewart, Doris Day, Marlene Dietrich and Gary Cooper.

Winston Churchill, of course, adored the place and attributed much of his success with a paint-brush to Marrakesh's extraordinary light. He has a £900-a-night suite named after him at La Mamounia.

The current craze is to block-book a riad - a town-house built around an open courtyard, normally within the walls of the old city - and fill it with your nearest and dearest for a long weekend. A friend of mine held her 40th birthday in this fashion last year, inviting 28 people. They paid for their own flights and accommodation, while she took care of all meals and entertainment - including quad-biking in the desert and a picnic in the foothills of the Atlas mountains.

Johnny McCall, an old schoolfriend of mine, was given a more modest Marrakesh fiesta for his 50th. The weekend was a present from his wife, and he got to choose one other couple to go along for the ride.

Curiously, as the four of us lined up to board our flight to Marrakesh, it became obvious that several of our fellow passengers were preparing for the mother of all Marrakesh parties. A few moments of eavesdropping established that two couples were celebrating wedding anniversaries, another was on a rare weekend away from the children and a third looked as if they would soon be ordering wedding bells. At the back of the plane, a group of insurance people in their 20s were readying themselves for three days of revelry otherwise known as "office bonding" before attempting to meet their financial targets for the year.

It's not difficult to understand Marrakesh's appeal. The flight takes little more than three hours and the weather is reliably glorious. Marrakeshis are warm and desperate to please. And it's cheap. On our first evening, we took a 10-minute taxi ride and gave the driver the equivalent of £12. His face lit up like a Catherine Wheel and he offered to be our driver for the entire weekend.

"There is no doubt that the growth in riads has added to the attraction of Marrakesh," says Chris Lawrence, who first arrived in the city in a Fiat 500 in the 1960s and now runs a specialist tour operator, The Best of Morocco, from his home in Wiltshire. "When I first started arranging holidays, most of our clients were travelling to Morocco for the first time. Now, some of them go every year and, in some cases, twice a year."

There are about 300 riads from which to choose. Some are aimed at budget travellers, others at middle-aged, middle-income people such as Johnny and me, while the most stylish and luxurious cost as much as a five-star hotel. We opted for Les Jardins de la Medina, just inside the city walls and close to the Royal Palace, because it seemed to offer the best of several worlds - authentic but with a spectacular leafy garden, and a swimming pool that was meant to be heated but felt strangely chilly.

Various Marrakesh experts advised us to avoid the city's most famous restuarant, Yacout, which is more of a tourist attraction these days. They were right - and they were wrong. The food is heavy and less than special but the interior and the courtyard and the view from the terrace provide an instant baptism in Marrakeshi outlandishness. Much the best meal during our stay, though, was to be found at Dar Moha in the Medina, where the omnipresent tagines took on a flavour all of their own.

Saturday was almost entirely given over to walking the streets with our official guide and haggling with shopkeepers in the souk. We shopped and never dropped. In fact, the more we shopped, the more we wanted to shop. I have always longed to own a proper leather hold-all but could never justify the cost. But in Marrakesh it didn't take me long to find one - made of camel skin - for less than £40.

After a spot of haggling the price came down to £30 and I almost felt embarrassed. Then it was only a question of filling it up with other goodies - leather slippers, a couple of belts, two lanterns and enough spices to open a curry restaurant.

Johnny's birthday evening was spent in one of the restaurants overlooking the Djemaa el Fna. The food was fine, if unmemorable, but the view of the snake-charmers, fortune tellers, men with monkeys on their shoulders, jugglers and belly dancers, the hiss of cooking emanating from the square's makeshift kitchens and the clouds of steam rising into the African sky were suitably intoxicating.

We took our Sunday morning, post-birthday party promenade at Yves Saint Laurent's restorative Jardin Majorelle, which the artist Jacques Majorelle opened to the public in 1947. Today it features some of the world's rarest cactuses, planted in and among palm trees, bamboos, lily-pools and tumbling bougainvillaea - all competing for attention with the striking blue external walls of the garden's Islamic Art Museum.

Given the choice - and a change in economic fortune - I would like to celebrate my own 50th by taking over Kasbah Agafay, which is about 20 minutes outside Marrakesh. We spent a day there and found it hard to leave just as the lanterns were being lit. It's a 150-year-old hilltop fort that Abel Damoussi, who spends half the year in London, has transformed into a 20-room hotel and spa.

I would recommend beginning with drinks in the garden next to the swimming-pool, followed by dinner on one of the terraces or ramparts and a night in one of the Caidal tents in the garden, which have four-poster beds and vast mosaic baths. Agafay is a favourite of Rory Bremner and almost 75 per cent of its guests are from the UK. After just a taste of the sophisticated decadence that Marrakesh has to offer, you will no doubt want to join the regular exodus.

- Mark Palmer