Symzonia: A Voyage of Discovery is a piece of fictional travel literature published on November 2, 1820, by Jonathan Seymour. It was written under the pseudonym Captain Adam Seaborn and its true authorship is uncertain, although stylometric analysis performed by Paul Collins suggests that the author was Nathaniel Ames. The book is premised on the earth's being hollow and was influenced by the theories of John Symmes. The account by the fictional Captain Seaborn details a voyage from the United States in which Captain Seaborn leads a crew of sailors to the center of the Earth.