In 1977, the first fast breeder nuclear reactor in the world to provide electricity to a national grid was shut down for the last time. The Dounreay Dome on the North coast of Scotland, near Thurso, Caithness, was completed in 1958 and its silhouette later became an emblem of the Atomic Age. As the decommission of the entire site proceeds, incorporating even other defunct nuclear reactors and associated facilities, the question arose whether the Dome can and should be preserved as cultural heritage for the benefit of future generations. Using the example of the legacy of the nuclear power station at Dounreay, this paper discusses the question what it means to preserve something for the benefit of future generations.