A Caribbean jewel with a rough edge

It wasn't the most auspicious of starts. Three hours into our Air France flight from Paris to Bogota the pilot announced that we had to make an emergency landing. The word 'emergency' isn't one you necessarily want to hear at 30,000ft. Especially when the plane hasn't had time to burn off its fuel load.

The reason for the unscheduled landing soon became clear: a woman passenger had been taken ill a few hours into the flight and her condition was deteriorating. A doctor suggested she needed urgent hospital care. And so we swooped down on the tiny island of Terceira in the Azores and, amid cloud and sheeting rain, landed safely at Lajes air base.

The woman had been on a flight from Bogota to Paris earlier that day but, on being refused entry to France, was put on the next flight back to Colombia. The little bags of cocaine she had swallowed in Colombia should have been exiting her body at about that time in some Parisian suburb under the watchful eye of an associate. But it wasn't to be and her luck was running out until the doctor suggested that a tiny strip of land in the mid-Atlantic might just save her life.

And so, even at 30,000ft above the Atlantic, drugs were managing to weave their way in to the Colombian narrative - a story that has dogged the country for the past 20 years. Some of the people who would have snorted the woman's decanted cocaine might spare a thought for the deep scars the drug has left in its wake. It's an industry driven almost entirely by demand from Europe and America, but the detritus and death that it brings are washed up almost exclusively in Colombia.

After an unscheduled overnight in Bogota, I eventually reached Cartagena, where the plan was to learn some Spanish and sample life on Colombia's Caribbean coast. To further this attempt at total immersion, I had rented a small apartment close to the city centre and booked some lessons at the local Spanish language school.

On its website the school looked bright and shiny, with alert-looking students carrying folders and walking purposefully across an impressive campus. But that was on the internet. Rolling up on the first day to find a 'campus' of two roughly hewn brick buildings with no windows and outdoor toilets was a surprise. And not the last one I would encounter in this country. And while the schoolroom didn't have windows, it did have wireless internet - of far more importance to the students - and the teacher was fantastic, which worked just fine.

Colombia has only recently stepped into the tourist mainstream as it strives to cast off the legacy of one of the world's longest-running civil wars. For the past 30 years it has been riven by myriad armed conflicts, and though the situation has improved dramatically over the past five years, problems remain, especially in remote places where the Revolutionary Armed Forces of Colombia (Farc) - revolutionaries turned narco-guerrillas - are still active. The country has earmarked tourism as a significant revenue stream for its nascent economy, and the forthcoming film of Gabriel Garcia Marquez's Love In The Time of Cholera will do much to thrust the country, and particularly Cartagena, centre stage.

The film, by British director Mike Newell and starring Javier Bardem, was originally set to be shot in Brazil; it was switched to Cartagena only after the Colombian vice-president (himself the victim of a kidnap, chronicled, coincidentally, in a work of non-fiction by Marquez, News of a Kidnapping) personally lobbied the film's producers to reconsider. They did, but only after the government provided armed security to allow the insurers to sleep easily. This will be the first English-language adaptation of Marquez's work, and since much of it is set in Cartagena, it is fitting that the port city should play host.

While much of Colombia is now safe (though not necessarily easy) to travel in, no one should assume that its problems are a thing of the past. In my final week there, a roadside bomb killed nine soldiers who were on a mission to destroy a coca plantation. The attack received only a small mention in the local paper.

Colombia has got used to drugs and the death toll that trails in their wake. This bloodshed dates back to the mid-Sixties, when Farc and the National Liberation Army (ELN) began a campaign of armed resistance against what they saw as an iniquitous government driven by rampant capitalism which had failed to empower the poor. Power was seen to lie in the hands of a leftover Spanish elite, so racial undertones also informed the ideology in a country where huge numbers are of mixed descent. Right-wing paramilitary groups sprang up to battle the left-wing guerrillas. And so a terrible, bloody civil war began.

This mixed heritage is one of the first things that tourists to Cartagena will notice - not only in the brown, black and occasional white faces around the city, but in its architecture and music, too. The city was one of two South American slave ports, and around 160,000 Africans were transported here. The second thing you'll notice is the heat. Then the noise, and the dust. The tourist officials are busy - as are the property developers - promoting a particular vision of this city as a picture-postcard jewel of the Caribbean, with its immaculately preserved central city area of stunningly pretty streets and buildings. But the truth is that this is a complicated city of many faces, some of them rather less than glamorous.

Cartagena was founded in 1533 by the Spanish, who designed a walled defence around the city to protect it from pirate attacks. Though the raiding parties (among them Francis Drake) still came and plundered, at least the walls helped protect the city's buildings. For that reason, Cartagena boasts an extravagantly well preserved inner-city area of beautiful colonial architecture.

It is this inner walled area - El Centro - for which Cartagena is famous. It is divided into several parts, all with very different characters. The streets and lanes are sumptuous, with staggeringly impressive buildings - the cathedral, the Central Bank and the Gold Museum among them - and the tiny narrow streets are full of pretty two-storey houses where flowers drape over wooden balconies. Here there is a growing number of boutique hotels, restaurants, cafe-strewn plazas and elegant shops. Stop a while at the only cafe in Plaza Bolivar and watch as a dance troupe entertains the park regulars and tourists with an acrobatic display of local dance; or wander up to Plaza de San Diego and mingle with the artists hawking their wares or hang out with the locals and just people watch. At the nearby Bovedas (the vaults built into the 40ft-wide city walls) there are dozens of little shops selling jewellery, clothes and artwork, and steps to take you up to the top of the walls, giving views across rooftops on one side and the Caribbean on the other.

This is the part of Cartagena where the tourists from the cruise ships are decanted and spend their money (£75 a day according to the tourist officials). But they confine their wanderings to a very small part of the walled city, before being bussed back to the port and on to their next stop. It is great to drift aimlessly through these precious streets, but this is a very small part of Cartagena, a tiny part of Colombia, and offers only a selective view of the city and country.

A short walk from here, across one of the few large roads, is a different world. In the Matuna area, the streets are bustling, with tiny food stalls frequented by local workers, vendors lining every inch of the footpaths selling anything from Zippo lighters to mobile phones, dozens of hawkers dragging their wares and shouting constantly as they go, and cars permanently beeping in a city centre almost without traffic lights. Here the peace and calm of El Centro seems a world away, but in fact it's less than five minutes. This is the working, sweating, bustling part of the city, with its commercial and financial buildings, markets and fruit stalls. These are Cartagena's veins, heart and lungs, cleverly hidden from view in the 'jewel of the Caribbean'.

A few streets on, the tempo changes again in the wonderfully named Getsemani. This was the traditional home of the African slaves, and although the architecture mirrors that of El Centro, it feels like a poorer, dirtier cousin. This is where the students come to flop for £4 or £5 a night as they work the gringo trail down Latin America, downing mojitos and beers in the Club Havana and swapping tales of derring-do. Outside, as night closes in, Getsemani becomes sparsely populated - it has a reputation as a feral home to pimps and prostitutes and crazed addicts of one sort or another. Edgy maybe, but assuming streetwise caution, it never seemed dangerous.

And yet there is more to this city. The woman who came to tidy my flat a couple of times a week lived beyond the walled area and spoke passionately about the poverty that rings a city where, within minutes of the boutique hotels, you can find shanty-town living conditions - huts that are rudimentary at best and sanitation facilities that are far worse. This is where many of the people displaced by years of guerrilla warfare have come to settle. The smell of rubbish and urine is preferable to the sound of gunshots.

Yet current President Alvaro Uribe Velez has had a significant impact in routing many of the murderous guerrillas, of both left and right, who had plagued the country. They have fled to the jungles and the remotest areas, where Farc members tend coca plants and feed their drug mules. They have long since cast aside any pretence of a political struggle. Erstwhile fellow guerrillas from ELN have taken a more pragmatic approach - laying down their arms and joining the political process.

The Uribe-sponsored war on drugs has been conducted under the auspices of Plan Colombia - a George Bush-backed programme to eliminate one of the most plentiful sources of cocaine in the world. Uribe, whose father was murdered by Farc in 1983, has clearly made great improvements by strengthening the rule of law and making large tracts of the country passable. But he is not beyond criticism: many are suspicious of his links to right-wing paramilitary groups who, it is alleged, spy on union activists and opposition groups.

In the week I arrived a huge row broke out when former US vice-president Al Gore announced that he would refuse to share a public platform on climate change with Uribe because of the President's alleged links with the paramilitaries. Uribe's response was swift: he commandeered all the TV stations the next day (public and private) and delivered a two-hour riposte to Gore.

People living in some of the less affluent barrios complain about paramilitary intimidation, but elsewhere in this country a new and thriving Colombia is in evidence. The swish hotels and smart restaurants could vie with many in Europe. Cities such as Medellin and Bogota, previously synonymous with drugs and gang violence, are emerging as bright, shiny advertisements for Colombia, as a renewed economic confidence drives these cities forward.

Next to the walled centre of Cartagena sits Bocagrande, a finger-shaped piece of land which sports high-rise flats, tourist complexes and a frenzy of skyward development. Bocagrande is like a tiny piece of Florida transplanted south, the ostentatious wealth and comfort at odds with the city's more deprived barrios.

Cartagena is ringed with beaches, though they have the grey pallor of city beaches and fall short of the tropical Caribbean ideal one might expect. Many visitors make for the Islas del Rosario, a group of small coral islands 30 miles off the coast. Here you can sample the famed turquoise water and snorkel for hours among the luminous fish. These islands are a delight, and ferries run from the city early in the morning and return late in the evening. It is a welcome relief from the heat and sweat of the city.

For adventures further afield, visitors head to the vast Parque Nacional Tayrona at the foot of Sierra Nevada de Santa Marta, where the jungle gives way to white sandy beaches. The landscape here can switch from arid to lush rainforest. Trekking in the forest is now safe, though many visitors seem happy to simply patrol the park's many bays, where the shallow bright waters are excellent for snorkelling. Accommodation is fairly basic in the park, ranging from hammocks slung from trees to my - at most - one-star concrete room.

Nearby in Santa Marta and the coastal town of Taganga there is a busy diving industry, with many young backpackers stopping off for four or five days to get basic diving qualifications. And close at hand is Ciudad Perdida (the Lost City) a 10th-century settlement built by the Tayrona Indians, and one of the most important archaeological sites in South America. Since its stone structures and dozens of terraces are set deep in the mountainous forest, it is not easily reached. The only route in is with an organised tour. The round trip takes six days, often trekking through - depending on the time of year - blistering humidity or muddy swampy conditions.

On the way back from this region, flagging an inter-city bus outside Canaveral near Parque Tayrona, I immediately noticed that this wasn't a routine backpacker tourist bus. Instead, it was filled with locals and jammed with suitcases, packages and boxes strung together and stuffed full to breaking point. I wondered why - but not for long. The first army checkpoint stopped the bus after about 20 minutes. A rigorous search of the luggage hold and the inside of the bus ensued while we waited on the roadside for 30 minutes. As we were finally waved through, I noticed one of the higher-ranking soldiers walking off with a few boxes of Johnnie Walker Black Label. Job done.

Only it wasn't. We were stopped again by a different branch of the army after another 20 minutes, and this time all the male passengers were ordered off. The bus was again combed. It turned out it had come from a neighbouring city close to the Venezuelan border, where contraband whiskey and cigarettes are routinely sold to street traders who flog them in Barranquilla and Cartagena for knock-down prices. They had stocked up over the weekend and were on their way home. Numerous searches ensued at intervals of roughly 30 minutes, carried out by different parts of the army (customs, transport security). The two-hour bus journey slowly, very slowly, mutated into a five-hour marathon. I stopped counting at stop-and-search checkpoint number six, when the male passengers were again told to get off. We were ordered to spread our arms against the side of the bus to be body-searched by youthful soldiers toting assault rifles not quite as tall as themselves.

Relaxing holiday situation? Not terribly. Interesting? To begin with. But after six searches the overwhelming feeling in the bus was of scratchy irritation and boredom. It seemed a lot of bother to go to for a few bottles of whisky. But I took a slightly different view next morning when I learnt that the previous day at a different checkpoint - in a very different part of the country - the army had stopped a bus and found a woman carrying 700 bomblets under her clothes.

She was, the army said, on her way to a Farc training camp to deliver her cache. On reflection, maybe he deserved the Johnnie Walker.

A backdrop for screen romance

The forthcoming film Love in the Time of Cholera was shot in Cartagena and is based on the 1985 novel of the same name by Gabriel Garcia Marquez.

While the city that provided the setting for the tale of a 50-year love triangle was never named in the book, it was widely taken to be Cartagena, which it resembles very closely and is where Garcia Marquez spent his youth. Set in the late 19th century and the first decades of the 20th, it deals with unrequited love and explores the idea that while there is something noble about suffering for love, lovesickness is a disease, like cholera. The narrative opens with the elderly Fermina Daza being widowed when her husband, Juvenal Urbino, falls to his death from a mango tree while trying to rescue their parrot. After the funeral her childhood boyfriend, Florentino Ariza, declares he is still in love with her, and the tale flashes back to show his lifelong painful obsessive love for her - undimmed by 622 affairs.

The film, directed by Mike Newell with screenplay by Ronald Harwood, is released in the US on 16 November. The UK release date has yet to be confirmed. Javier Bardem plays Ariza, Benjamin Bratt plays Urbino and Giovanna Mezzogiorno plays Daza. Cartegena's cobbled squares, canal, cathedral, mansions, turreted walls and the Magdalena River form a backdrop for the movie, even though Colombia was originally discarded as a potential film location.

For the duration of the filming, 5,000 jobs were created in the city and the government hopes the film will boost tourism.

Essentials

John Mulholland organised his flights with Journey Latin America (020 8747 8315; journeylatinamerica.co.uk). A return fare to Cartagena costs from £722, including taxes. The company can also design a 13-day itinerary around the country. Prices from £1,483pp (based on two people sharing) including transfers, accommodation and guided excursions, but not international flights.