Trail of the unexpected: West Africa

The masons of the Niger Delta city of Djenné are uniquely talented, says Jane Labous

The good news: the Foreign Office's advice for countries seen as risky now boasts a natty, colour-coded map showing safe areas in green. Parts where Brits are advised not to go are in red. The bad news: Djenné, whose Great Mosque is the biggest mud building in the world, is in the "Advise against all travel" part of the Mali map. Yet, having won the Royal Geographical Society's Journey of a Lifetime Award to make a documentary for BBC Radio 4 on Mali and the mud masons of Djenné, I was determined to go.

I had been assigned a translator and driver called Amadou. With the temperature topping 40C every day since I arrived, the back of his car was even hotter than outside, but we managed a lively stream of discussions. Nevertheless I was a lot thinner after sweating half my body weight away during the eight-hour drive to Djenné from the capital, Bamako. The roads gradually dwindled into the red dust until there's was nothing left but dirt track. And then there was Haroun, Amadou's cousin, a true African entrepreneur who fulfilled his roles as navigator, negotiator, escort and holder of the windbreak with the elegant fluidity of the desert sands.

There's magic enveloping Djenné, not because of its location – clinging to the inland River Niger Delta, 345 miles south of Timbuktu and the southern edge of the great Sahara desert; nor its peculiar architecture (made entirely of banco, or river mud mixed with rice husks), a twisting, crumbling jumble of earth huts, alleyways, staircases and dreaming spires. No, the real magic comes from Djenné's inhabitants.

In 1300, the townsfolk cavorted in front of their great mud edifice while drinking millet beer. Sultan Kunburu later tore the first palace down after converting to Islam. He rebuilt it as a mosque.It fell into a state of disrepair during the early 19th century under ruler Seku Amadu; but was restored in 1907. There are, it's said, virgin sacrifices hidden in the town walls.

Djenné's mason magicians are the most respected members of the community. The ancient art of mud masonry is passed down through generations here and only the masons of Djenné know how to work with the mud to make banco and repair the mosque, casting spells on the town's buildings to keep them intact.

In the dusty old chests of Djenné's archives, black and white magic spells are still kept hidden from the eyes of prying strangers.

There's definitely something enchanted about the Great Mosque, with its smooth mud walls rising from the earth and its three towers with rounded minarets pointing skyward, each one topped with a white ostrich egg. Dark, spiky palm wood scaffolds poke out all over it. It's primitive, menacing and beautiful all at once. It stands on a mud platform above the town square, with the kind of central staircase that would satisfy the most demanding of cloaked overlords preparing to make sacrifices.

Djenné did a roaring trade in gold, salt and slaves in the 17th century, and while men and women are no longer sold on the dusty square beneath the mosque, there's still much that is medieval here. At sunrise, cart drivers feed their horses as passengers leave on decrepit old buses for Mopti, Gao and Timbuktu. Mid-morning, clusters of ragged kids clutching blackboards gather for Koran school, while nine-year-old apprentices tread mud and rice husks into banco by the western wall and the master masons plaster it onto the mosque roof; dark figures against the white hot African sky.

I met Djenné's head mason, Kum Baba. He is the man in charge of replastering this huge mud building, a task that goes on all through the dry season so that the mosque stays intact during the rains. He showed me how to plaster a wall using my hands, slapping the banco on and smoothing it out like a big mud pie. Then we squashed into a tiny, crumbling room at the top of his mud house.

He told me how, when he was six, his uncle used to take him out in the dead of night for magic training. "I was scared," he muttered in Bambara, as the sweat broke out on my forehead.

"He taught me bad spells; if they got into the wrong hands, they'd be dangerous." Later the magician mixed millet seed, feathers and charcoal in a bowl, chanting a spell under his breath and scattering the mixture over the foundations of a house. "It brings prosperity and luck," he explained. "I can't tell you the spell, because it's a deadly secret, but very powerful."

In the afternoon, as the sky pulsated with heat, everyone sat down, apart from the kids, who kicked around desultorily in the dust until the day cooled and the square came alive with silhouettes. Women tied bundles of kindling and the kids played on strange chariots that littered the square.

A butcher held a torch in his mouth as he chopped goat meat. A lame boy on crutches stared. Cooking fires glowed red. There was muffled laughter and music blaring from radios; the zoom of a moped and the pad of donkey hooves.

Men in robes hurried to the mosque and the call to prayer rang through the heat and the dust.

It was mesmerising, rather than menacing and I felt as safe as houses – even if they were made of mud.

'Journey of a Lifetime' is on Radio 4 on Monday at 11am

Travel essentials: Mali

Getting there

* The main links to the capital, Bamako, are on Air France (0870 142 4343; via Paris, Brussels Airlines (0905 609 5609; via Brussels, and TAP Portugal (0845 601 0932; via Lisbon.

Staying there

* Campement de Djenné (also known as the Hotel Houber): 00 223 242 0497. Doubles from £10 per night.

Staying safe

* "If you plan to travel to any of the areas of Mali where we advise against travel, says the Foreign Office, "you are advised to fly. If travelling overland, it is essential to plan your journey in advance and inform local authorities (police and/or army) before leaving Bamako. A reputable local driver/ guide is recommended."

* The writer attended a Hostile Environments and Emergency First Aid course, courtesy of Centurion (