In the heart of the Malian city of Djenné, the world’s largest mud-brick building dominates the skyline: the Great Mosque. First built in the 13th century, it was reconstructed in 1907 in the distinctive Sudano-Sahelian style, recognizable by its massive buttresses, minarets topped with decorative pinnacles, and toron—wooden beams that serve both as ornamental elements and as footholds for masons during maintenance.

Inscribed as a UNESCO World Heritage Site in 1988, the mosque is not only a masterpiece of architecture but also the focal point of a unique community tradition: the annual re-plastering.

Each year, at the end of the dry season, the people of Djenné gather to give the mosque a renewed skin of clay. The banco—a mixture of clay, water, and plant fibers—protects the walls from the oncoming rains. But under the wear of wind, heat, and weather, the coating erodes and must be renewed. This is no mere repair job: it is a celebration, a ritual, and a manifestation of the city’s unity.

In the days leading up to the event, earth is taken from the Bani River, mixed, and left to “mature” in large pits. Then, on the appointed morning, men, women, and children divide the work: some carry buckets of mud, others spread it on the walls using the toron as handholds, while the city fills with the sound of songs, laughter, and friendly competitions between neighborhoods.

The tradition dates back to the 1907 reconstruction and preserves the ancient skills passed down by the master masons, the barey ton. It is also a learning moment for the younger generations, who absorb both the craft and the importance of heritage. Since 2016, the mosque has been listed as a World Heritage Site in danger due to climate and security threats, yet the community continues to mobilize, sometimes under more challenging conditions, to sustain this ritual that protects both the building and the spirit of the city.

In 2025, once again—just before the June rains arrived—the re-plastering brought together the entire population, a vivid reminder that in this city on the inland Niger Delta, earth is not just a building material but a living link between past and present.