Mounds of earth, stone and concrete are what remain of the hideouts built by both Spanish Republicans and Franco's fascist army alike. Erosion by water, wind, and sun has reduced this architecture to bones half-buried in the ground. Moss and lichen cover the structures, slowly metabolizing their material and bringing it back to another mineral and organic matter. These artificial caves mimic the natural qualities of cavities in rock providing shelter for soldiers against bullets and bombs. They also served to provide an advantageous position for the fascist army to target incoming infantry from Allied forces on the shores of the Costa Brava or the foothills of the Pyrenees. They would serve to help kill other men from a safe distance. Yet, these coastal bunkers, built by the dictator in Catalunya, were never used. By the time they were completed, the style of war had started to change from a conventional World War II of artillery and occupation to a Cold War of nuclear threat. In contrast, the bunkers built by the Republicans were used as a defense against fascist forces. To hide from air strikes that indiscriminately targeted civilians and soldiers. Amongst the republicans were international participants, such as the Abraham Lincoln Brigade, committed to anti-fascist resistance and presaging the rise of fascism around the world. The Spanish civil war ended with the triumph of fascism and Christian nationalism which lasted decades. Although these vestiges of conflict do not readily provide a moral lesson, they do remind us of an infrastructure of violence—men transforming nature into defenses and weapons. Ultimately though, nature comes back to reclaim this built environment by rotting the structures and making new life.