The oldest and most important of Timbuktu's three UNESCO World Heritage mosques, built in 1327 on the orders of Emperor Mansa Musa and still in active use today. It is constructed in the distinctive Sudano-Sahelian style: sun-dried mud brick with protruding wooden beams that form the scaffolding used for annual replastering. The whole community participates in the annual replastering ceremony each spring, which is as much social festival as building maintenance.
The mosque can hold up to 2,000 worshippers. Non-Muslims are generally not permitted inside, but the exterior with its three towers and organic mud-brick forms is spectacular in the afternoon light, and the surrounding neighbourhood of narrow sand-floored alleys is worth wandering. One of the towers serves as a minaret; the second is the imam's tomb; the third marks the corner of the building where Mansa Musa himself is said to have prayed.