Grand Mosque of Djenna

The Great Mosque of Djenné in the West African country of Mali was originally constructed in the 13th Century. It gradually grew to be an enormous structure before it fell into ruins by the 19th Century. From 1906-7, it was rebuilt using adobe — the original building material. It is today the largest adobe structure in the world. The Great Mosque is built on a raised plinth platform of rectangular sun-dried mud bricks that are held together by mud mortar and plastered over with mud. The walls vary in thickness between 50 to 80cm, depending upon their height. These massive walls are necessary in order to bear the weight of the tall structure and also provide insulation from the sun’s heat. During the day, the walls gradually warm up from the outside; at night, they cool down again. The mosque’s prayer hall, with ninety wooden pillars supporting its ceiling, can contain as many as 3000 people. This helps the interior of the mosque to stay cool all day long. The Great Mosque also has roof vents with ceramic caps. These caps, made by the town’s women, can be removed at night to ventilate the interior spaces.