A Strange Manuscript Found in a Copper Cylinder is the most popular book. The main story of the novel is the narrative of the adventures of Adam More, a British sailor shipwrecked on a homeward voyage from Tasmania. The satiric and fantastic romance is set in an imaginary semi-tropical land in Antarctica inhabited by prehistoric monsters and a cult of death-worshipers called the Kosekin. After passing through a subterranean tunnel of volcanic origin, he finds himself in a lost world of prehistoric animals, plants and people sustained by volcanic heat despite the long Antarctic night. A secondary plot of four yachtsmen who find the manuscript written by Adam More and sealed in a copper cylinder forms a frame for the central narrative. They comment on More's report, and one identifies the Kosekin language as a Semitic language, possibly derived from Hebrew. In his strange volcanic world, More also finds a well-developed human society which in the tradition of topsy-turvy worlds of folklore and satire.