The Czech hedgehog is an anti-tank defense obstacle made up of angular metal bars linked together. Czech hedgehogs were widely used during World War II by Soviet forces. They were made with any metal part or even with train rails. They also proved to be extremely effective in urban combat conditions because a single piece could block an entire street.At the beginning of the 21st century, the housing utopias from the Athens Charter are completely shipwrecked in the impoverished peripheries of the global megalopolises. With the fragile contract between capital and the social body definitively broken, full of ghettos and walls, borders, enclaves and fortified areas for the privileged, that dream city is today a battlefield.This work represents the tensions in macrocities due to the scarcity of resources that pose an eminently urban scenario of war, of neighborhood-to-neighborhood struggle, and provide a justification for the endless war against the dispossessed.