In its earliest forms, descriptions of an underground world were prompted by the existence of caves and grottoes. The underworld held a strong fascination for older traditional cultures, in terms of the afterlife, for instance (the Realm of the Dead, Hades, etc., from Orpheus to Dante’s Inferno); and in myth and folklore as the home of various creatures (benign and threatening), including elves and fairies, dwarfs and trolls, and even giants and dragons. But in terms of depictions of inhabited imaginary worlds beyond those of simple cave dwellers, there are few examples before the 18th century. Then, in the space of twenty years, three different approaches to the imagination of the subterranean world appeared. In 1720, Tyssot de Patot published his La Vie, les Aventures et le Voyage de Groenland du Réverend Père Cordelier Pierre de Mésange. Avec une relation bien circonstanciée de l’origine, de l’histoire, des moeurs et du Paradis des Habitans du Pole Arctique, which depicts people living in underground cities near the North Pole. In 1721, the anonymous Relation D’Un Voyage Du Pole Arctique Au Pole Antarctique Par Le Centre Du Monde, Avec la Description de ce périlleux passage, & des choses merveilleuses & étonnantes qu’on a découvertes sous le Pole Antarctique recounts a passage through the Earth and introduces the idea of the “Holes in the Poles.” Finally, in 1741, Ludwig Holberg published Nicolai Klimii iter subterraneum, Novam Telluris theoriem ac Historiam Quintae Monarchiae adhuc nobis incognita exhibens, which was immediately translated into a number of European languages (The Journey of Niels Klim to the World Underground, with a new theory of the Earth and the History of the previously unknown Fifth Kingdom) and which introduced the idea of the Hollow Earth.