That's made of mud ????

 
The Great Mosque of Djenné is the largest mud brick building in the world and is considered by many architects to be the greatest achievement of the Sudano-Sahelian architectural style, albeit with definite Islamic influences. The mosque is located in the city of Djenné, Mali on the flood plain of the Bani River. The first mosque on the site was built in the 13th century, but the current structure dates from 1907. As well as being the centre of the community of Djenné, it is one of the most famous landmarks in Africa.

The site has been the location of a mosque since the original building was commissioned by Koi Kunboro in 1240, before Djenné emerged as a major city of the empires of Mali and later Songhai. Peul conqueror Amadou Lobbo, who took Djenné in his jihad, ordered the original mosque demolished in 1834. He considered the original structure, which had been modified from a palace, to be too lavish. The only portion of the original building that still survives is an enclosure containing the graves of local leaders. A re-creation of the original was completed in 1896 but was subsequently demolished to make way for the current structure. Construction on the current Great Mosque began in 1906 and was probably completed in 1907 or 1909.