The Djinguereber Mosque has been the Friday mosque of Timbuktu since about 1327, ordered by Mansa Musa on his way home from Mecca. Most of what you touch on it is a season or two old. The building is banco: earth kneaded with straw and pressed on by hand, so close up the wall is worked rather than rendered, straw ends and the marks of hands still in it. Every coat goes on over the last. The timber stakes bristling out of the walls are toron, not decoration but permanent scaffolding, left in the mud because the masons will need them again. The stepped mud minaret lifts clear of the low sand streets from almost anywhere in the old town, so it is what you steer by.
Inside, close-set earth pillars run back in rows, and the deeper you go the more the heat falls away, until the only daylight is a few bars lying on the sand floor. The heavy doors, timber set with iron, are almost the only thing in the building that is not mud, straw and stone, and the light coming through them shows you how thick the walls are. Three courts separate the prayer halls, floored with bare sand, so nothing done in them makes a sound; they are the only part with sky over it. Each October, once the July-to-September rains have scarred the banco, a hereditary guild of masons leads the city up the toron poles to re-coat the mosque by hand. It is not run by the state or by UNESCO. Children carry water and mud alongside their grandparents, and that is the point of it. The day is how the technique passes on, and the reason anyone in Timbuktu still knows how to build in banco. For weeks afterwards the walls stand smooth and pale. The hands are still local; the wood is not. Mali can no longer grow beams long enough for the roof, so the timber for repairs comes from the forests of Ghana.