John Cleves Symmes Jr was an American soldier who fought with distinction against the British in the war of 1812. After the war, Symmes became the best-known proponent of the so-called ‘Hollow Earth’ theory, the idea (beloved of science fiction writers) that the Earth is hollow and contains other worlds within it, possibly inhabited by human beings.
Symmes believed that there were entrances to the Earth’s interior at the poles and campaigned for polar expeditions to be organised in search of them. After his death in 1829, fellow believers continued to argue that these ‘Symmes’s Holes’ existed. Needless to say, no expedition to the North or South Pole has ever found any trace of them.
Answered by: Nick Rennison