Armed with geological tools, a drone, three teammates and a four-wheel drive, geologist Pierre-Olivier Bruna ventured far off the beaten track into Australia’s Outback in the Northern Territory. His purpose: to study the geological history and structure of the McArthur Basin in an area called the ”Lost City” with peculiar stone pillars. The team specifically investigated natural cracks, called fractures, in the rocks to understand how fluids like groundwater or hydrocarbons flow through the rocks.