“Revolutionary” technologies or large technological systems are often deemed controversial, risky, or ambivalent. Diverging interpretations clash when technological objects, such as rockets, airplanes, or nuclear reactors, are exhibited in museums or at heritage sites, with profound implications for underlying concepts of historical education. This special issue explores the argument that histories of technology have often upheld a traditional view of modern linear progress but became the focus of controversies when the social, political, and cultural conditions of perceiving and remembering these objects changed. At former “places of progress,” visitors and exhibition makers are confronted with the remains of the Industrial Revolution, colonialism, two World Wars, the Cold War, the Age of Coal, the Space Age, the Atomic Age and the Digital Age. Exhibitions and displays have been used to explain, teach, or make sense of the advents, successes, and failures of high-tech projects. Understanding technological artifacts and corresponding sites such as Chernobyl, Peenemünde, and Hiroshima as well as structures such as factories or bunkers as sites of memory (lieux de mémoire, a term coined by Pierre Nora) shifts our attention to processes of remembering modern technologies and the cases in which established narratives of progress have been supported or challenged. Questions about the ethics of technology use often seem to subvert stories of the “heroes of invention,” leaving visitors with the impression of technological ambivalence. Attempts to teach and learn about history and technology via objects and sites have been complicated, politicized, and contested.