The mosque's first version rose in 1948, raised by a team of bricklayers from Djenné - the celebrated mud-architecture town downriver - led by the mason Lassiné Minta. As Niono's population swelled, the building grew with it, expanded in stages until the last major enlargement was completed in 1973. The techniques never changed, because they did not need to. Load-bearing walls and arches of sun-dried mud brick, floors and roofs of palm wood, matting, and packed earth: these are methods that have shaped the Sahel for centuries. What the Aga Khan jury celebrated was not novelty but continuity - the survival of a sophisticated tradition in a century racing toward concrete. The mosque, they wrote, showed that traditional forms remain one of architecture's strongest allies in keeping cultural identity alive.

Step inside and the scale reveals itself. The mosque covers 1,800 square meters; its main prayer hall alone spans 658, and a women's prayer hall rises across two floors. The interior is a hypostyle forest - sixty-eight pillars carrying the weight of those heavy earthen roofs, dividing the dim cool space into bay after shadowed bay. Outside, four minarets punctuate the form: a principal tower over the western entrance and three more clustered at the eastern end along the qibla wall, the side that faces Mecca. The whole structure has the hand-modeled, slightly organic quality of earthen architecture, as though it had grown from the plain rather than been set down upon it. In the flat light of the Sahel, its bristling silhouette is unmistakable.

Mud architecture is never finished. Rain erodes it, sun cracks it, and each year the community must replaster the walls - so the mosque is, in a real sense, remade by hand again and again by the people who use it. That ongoing act of care is part of what makes it remarkable, and part of why UNESCO added it to its World Heritage Tentative List in 2009 under the cultural category. The Great Mosque of Niono is not a relic preserved behind glass. It is a working house of prayer, sustained by the same skills that built it, standing as proof that the oldest way of building in the Sahel is also, still, a living one.