show Abstracthide AbstractThe Great Wall of China, one of the most symbolic and monumental human heritage sites ever built, is covered by a living skin composed of microbial communities. Strikingly, such microbiome covering this emblematic monument remains virtually unknown, which hampers any attempt to understand the role of this microbiome in its long-term conservation. Here, we investigated, for the first time, the microbiome of the Great Wall across arid and semiarid climates in a 600 km wall section built with rammed earth, and found that this structure was colonized by highly diverse communities of bacteria and fungi.