Like time travel, the idea of strange underground worlds was a fairly common theme of science fiction and fantasy. –Jim. 2:39 PM. Anonymous said… P.S. Although the Hillman car might well have inspired the Mighty Mole, another possible inspiration would be the Iron Mole–the invention … This features a mole-vehicle called the Cyclotram, which looks more like Carson’s vehicle than the Thunderbirds type of mole, although it doesn’t have the car look that Carson’s does. … …

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Silver Age Comics: The First Underground Comics?