At the height of the Cold War, nuclear weapons were seen not only as devices of destruction, but also as tools for progress. Project Plowshare was a bold attempt to use atomic explosions for more practical purposes: from digging canals and creating harbors to reshaping entire landscapes. This project was designed to push the limits of what seemed possible, but instead turned into an environmental disaster. How did Project Plowshare come up? What happened to it, and why did it fail in the end?