ABSTRACT
The underworld held a strong fascination for older traditional cultures, in terms of the afterlife, for instance; and in myth and folklore as the home of various creatures, including elves and fairies, dwarfs and trolls, and even giants and dragons. One of the earliest proponents of hollows and cavities within the Earth was the Jesuit priest Athanasius Kircher, who poured his encyclopedic knowledge into a variety of treatises, including the Mundus Subterraneus. The second and most familiar type of underground world is that set in cavities beneath the Earth's crust and follows from myths and legends about the obscure dwelling places of strange creatures. The most unusual and complex iteration of the world underground is that of the Hollow Earth. The inner worlds under consideration, whether located in caves or in some Hollow Earth, were for the most part "natural", with only minimal human intervention or technological development.
