https://phys.org/news/2018-10-tales-crypt-microbial-life-graveyards.html

The researchers, who took samples from the surfaces of 149 gravestones in the Cementerio de Montjuic in Barcelona, Spain; El Queremal Cementario in Valle de Cauca Province, Colombia; Dory Hill Cemetery in Black Hawk, Colorado; and other graveyards, recently published their results in the journal Environmental Microbiology.

"Rock surfaces like gravestones are challenging environments for microbes," says Fierer. "But despite exposure to high levels of ultraviolet radiation and sporadic access to water and nutrients, microbes are able to thrive there."