Following World War II in Europe, botanists such as R.S.R. Fitter in London, H. Sukopp in Berlin, and R. Kobendza in Warsaw studied the novel ecosystems emerging in the ruins of postwar cities, documenting ruderal nature (from the Latin "rudus" for rubble) and exploring how plants adapted to environments radically transformed by the war. These early studies engaged with unique ecosystems that are now recognized for their crucial role in mitigating the effects of the climate crisis in cities. In a similar vein, the Atlas of Ruderal Architecture project investigates architecture that, much like ruderal nature, arises in the wake of wartime ruination. Drawing on nearly a decade of research, the project traces how architects, engineers, and builders across Europe in the 1940s adapted to postwar conditions through salvaging, reusing, and recycling materials.