The sixth President of the United States advocated for a polar expedition to reach the world’s epicenter.

The one-term President hoped to support John Cleves Symmes, Jr., an American army officer, who proposed the radical notion that the Earth was composed of circular concentric spheres that left openings near the globe’s polar regions.

In the 1820s Symmes traveled across the United States lecturing on the Hollow Earth theory, and though his plan to locate an entryway eventually earned the President’s approval, Congress never authorized the expedition. Any remaining hope that Symmes could someday search for a pathway to the planet’s interior disappeared with the 1829 inauguration of Andrew Jackson, who believed the Earth was flat.