In the German Reich, the landscape became the central medium to experience Heimat. The exotic landscapes the colonies provided led to an unprecedented spatial expansion: from a distance, the nation itself could become Heimat. While this spatial ‘extensibility’ as well as its capability to establish identity has long been the subject of research, so far the temporal dimension of Heimat has received little attention. The new and unimaginably long periods of time the discovery and exposition of the geological time scale in the 19th century provided seemed not to affect the Heimat. Examining popular scientific writings from the years 1898–1931 by Alfred Götze and Wilhelm Bölsche, this article shows that in the German Reich along with the spatial expansion of Heimat a temporal expansion took place. Including prehistory and earth history, this temporal expansion reached far beyond locating the Heimat in the ‘good old days’. In the medium of prehistoric landscapes, the contemporaries could experience two versions of a deep time Heimat. A nationalist deep time Heimat localized national unity in the depths of time, thus promoting a more comprehensive and at the same time more abstract ‘national’ Heimat. An imperialist deep time Heimat helped to expose the ‘struggle for existence’ and promoted the expansion of the Heimat as the only possible way to preserve it.