"John Rieder notes, for example, that the rising thirst for exploration of alien worlds in fiction starting in the nineteenth century, cannot be detached from growing awareness of an impending disappearance of a certain kind of exploration. He remarks: If the Victorian vogue for adventure fiction in general seems to ride the rising tide of imperial expansion, particularly into Africa and the Pacific, the increasing popularity of journeys into outer space or under the ground in the late nineteenth and early twentieth centuries probably reflects the near exhaustion of the actual unexplored areas of the globe…. Having no place on Earth left for the radical exoticism of unexplored territory, the writers invent places elsewhere."