The Hollow Earth Monument

Capt. John Cleves Symmes was a philosopher and the originator of the Symmes Theory of Concentric Spheres and Polar voids, contending that the Earth is hollow and habitable within. A native of New Jersey, he entered the Army of the U.S. as an Ensign in 1802, afterward rose to the rank of Captain, and performed daring feats of bravery in the Battles of Lundy’s Lane and the sortie from Fort Erie. He died in May 1829 at the age of 49 years and 6 months.

Hamilton, Ohio · United States