<P> Timbuktu was a regional trade centre in medieval times, where caravans met to exchange salt from the Sahara Desert for gold, ivory, and slaves from the Sahel, which could be reached via the nearby Niger River . The population swelled from 10,000 in the 13th century to about 50,000 in the 16th century after the establishment of a major Islamic university, which attracted scholars from throughout the Muslim world . In the 1600s, a combination of a purge by a monarch who accused the scholars of "disloyalty" and a decline in trade caused by increased competition from newly available trans - Atlantic sailing routes caused the city to decline . The first European to reach Timbuktu, Alexander Gordon Laing, did not arrive until 1826, and it was not until the 1890s that Timbuktu was formally incorporated into the French colony of Mali . Today, the city is still inhabited, but it plays little role on the world stage . </P> <P> Timbuktu is located on the southern edge of the Sahara 15 km (9 mi) north of the main channel of the River Niger . The town is surrounded by sand dunes and the streets are covered in sand . The port of Kabara is 8 km (5 mi) to the south of the town and is connected to an arm of the river by a 3 km (2 mi) canal . The canal had become heavily silted but in 2007 it was dredged as part of a Libyan financed project . </P> <P> The annual flood of the Niger River is a result of the heavy rainfall in the headwaters of the Niger and Bani rivers in Guinea and northern Ivory Coast . The rainfall in these areas peaks in August but the flood water takes time to pass down the river system and through the Inner Niger Delta . At Koulikoro, 60 km (37 mi) downstream from Bamako, the flood peaks in September, while in Timbuktu the flood lasts longer and usually reaches a maximum at the end of December . </P> <P> In the past, the area flooded by the river was more extensive and in years with high rainfall, floodwater would reach the western outskirts of Timbuktu itself . A small navigable creek to the west of the town is shown on the maps published by Heinrich Barth in 1857 and Félix Dubois in 1896 . Between 1917 and 1921, during the colonial period, the French used slave labour to dig a narrow canal linking Timbuktu with Kabara . Over the following decades this became silted and filled with sand, but in 2007 as part of the dredging project, the canal was re-excavated so that now when the River Niger floods, Timbuktu is again connected to Kabara . The Malian government has promised to address problems with the design of the canal as it currently lacks footbridges and the steep unstable banks make access to the water difficult . </P>

What was timbuktu and why was it significant