Here is a look at Timbuktu and a brief guide to what remains of the city: OVERVIEW - Ansar Dine, which experts say has links to local Al-Qaeda factions, has gained the upper hand over its former rebel allies, the secular MNLA group, after the two routed government forces and seized control of Mali’s desert north in April. - Timbuktu has been a UNESCO World Heritage Site since 1988, but tourism has suffered from years of security problems with gunmen seizing three foreigners and killing a fourth on a street in Timbuktu last November. TIMBUKTU – HERITAGE SITE - The World Heritage Site comprises 16 cemeteries – eight of which have now been destroyed – and mausoleums. They were deemed essential elements in a religious system as, according to popular belief, they constitute a rampart that shields the city from all misfortune. - The most ancient mausoleum is that of Sheikh Abul Kassim Attouaty, who died in 1529. Other famous graves include those of the scholar Sidi Mahmoudou and of Qadi al-Aqfb, restorer of mosques. BUILDINGS - In the 15th and 16th centuries Timbuktu was an intellectual and spiritual capital and a center for the propagation of Islam throughout Africa. Its three great mosques – Djingareyber, Sankore and Sidi Yahia – date from that period. Although regularly restored, they are under threat from desertification too. - The Mosque of Djingareyber was built in 1325. Between 1570 and 1583 the Qadi of Timbuktu, Imam al-Aqib, had it reconstructed and enlarged. The central minaret dominates the town and is its most visible landmark. A smaller minaret on the eastern facade completes the profile of the mosque. - Like Djingareyber, the Mosque of Sankore, built during the Mandingue period, was restored by the Imam al-Aqib between 1578 and 1582. The Mosque of Sidi Yahya, south of Sankore, is believed to have been built around 1400. The mosque door was smashed by Ansar Dine fighters Monday. MANUSCRIPTS - Timbuktu’s manuscripts offer an unparalleled window into societies and intellectual traditions from the late 15th century onward, but for decades they have been largely inaccessible. - This vast legacy is on the verge of being lost due to brittleness, termites, insects and the weather, as well as illegal sale, mostly to foreigners. - Many manuscripts are written in local vernaculars, while others are in archaic forms of the present-day languages of Songhai, Tamasheq and Fulfulde. The Timbuktu foundation says there are about 700,000 documents. Some record complex genealogies and scientific theories. - During the last 200 years, most of the manuscripts have been concealed, often buried or hidden to safeguard them from colonial agents, lawlessness and political instability. Today, the manuscripts are mostly in the hands of local libraries and private owners. But since April, they have been increasingly hidden away for safety. ORIGINS OF THE CITY - Mali is named after an ancient empire which grew rich from trans-Saharan trade through the city of Timbuktu. The historically important city,founded in 1100 by Tuareg nomads, was once the richest in the region and was seen as a trading post on the trans-Saharan caravan route. Timbuktu was captured by the French in 1894 and in 1960 it became part of the newly independent Republic of Mali.