It's dawn on market day in Djenné. Camel caravans have assembled outside the city and stalls are being set up on the square in front of the great mosque.

You're in luck: a kindly patrician allows you to climb on to his roof and watch the scene unfold.

Townsfolk and nomads mix in a colourful tableau: bright fabrics and boubous are for sale, as well as mounds of cotton, grains, basketware and exquisite silver and gold jewellery. The chant of Allahu Akbar rings out from the mosque towers.

This is surely one of ancient Africa's great spectacles. The mud mosque, with its minarets and pinnacles, appears to be straight from the pages of a fairy tale. Its architecture is different to anything you've seen before, like a dribbled sandcastle.

There are few better places to take in the mud cities of West Africa than in central Mali. In urban centres such as Djenné and Timbuktu, you can witness the flowering of Western Sudanese architectural style. These unspoilt gems look much as they would have when the great salt, gold and slave caravans still traded across the Sahara, making them some of the most powerful cities in West Africa.

Although founded in the 13th century, Djenné's great mosque is a modern replica of the kind of structures that preceded it. This is reputedly the largest mud building in the world and surely one of Africa's most beautiful. The three minarets are each more than 10 metres high and pierced with wooden toron (stakes) that act as permanent scaffolding. Every year the townsfolk turn out in their hundreds to replaster the walls.

This is an organic, sculptural structure whose fluid lines are constantly being altered by the effects of the elements … and by human hands.

But it's not only the mosques of Djenné that impress. Simply wander the streets and winding alleys to witness some of the finest examples of domestic Malian architecture. The multi-storey houses have terraced roofs and tall, often ornate, potiges (facades). Inside are cloistered courtyards, the realm of women in this strictly Muslim society.

The builders of Mali are revered as great artists, even magicians. The masons of Djenné practise methods handed down in their guild since medieval times. Known as bareys, these men carry few tools, save for a trowel to cut and smooth the mud walls. The mortar is mixed by many feet, the bricks moulded by hand and large structures are erected without plans or even a plumb line. Magic spells protect the houses from harm or interference.

Further down the Niger lies fabled Timbuktu. Once an important trading city and centre of Islamic learning, the place now lives in the shadow of its medieval glory.

The town's showpiece is the Djingareyber Mosque. Built in 1325 by the Andalusian architect Es Saheli, it boasts an imposing minaret and a number of conical towers. The main, colonnaded prayer space can hold well over a thousand worshippers and its thick walls keep the interiors relatively cool in the desert heat.

A fire destroyed Timbuktu in 1512 and the subsequent reconstruction followed Arab and North African traditions. Consequently, the dominant form of architecture here is rectilinear, flat-roofed houses, which are often multi-storeyed and built from sun-dried mud bricks.

The best way to take in the beauty of Timbuktu is from the back of a camel, arriving at dusk, the faint lights of the town floating ethereally above the dunes. It is then that these mighty ships of the desert are at their most beguiling … cities made from nothing more than earth mixed with Niger water.

Published by arrangement with Getaway magazine. For the full story, see the February edition of Getaway.