In this article, I examine “underground memories” to demonstrate how they serve as resources for resistance in the urban margins of Colombia. I focus on their relations with the urban fabric, looking at the ways the walls of Bogota and Medellin are used as canvases for spreading images and narratives about the conflict. I suggest that murals representing the violence serve as a repository for memories; they challenge hegemonic narratives and contribute to the recovery of public space. Through the portrayals of killed teenagers, suspect military officers and even drug cartel bosses, murals in both cities broaden the narrative on the recent past, including events that the Colombian state is still reluctant to unearth.