If you thought the “flat Earth” theory was the craziest conspiracy you’d hear about all year, think again. Because there’s a growing community of people convinced the Earth is hollow, with a race of ...

In the middle of a city park in Hamilton, Ohio, you can find a peculiar monument to Capt. John Cleves Symmes and his Hollow Earth theory. The time-and-weather-worn stone obelisk, topped by a metal orb ...

Like aliens above, the notion that there’s life below the Earth’s crust is catnip to conspiracy theorists. A recent Telegraph article recapped a statement made in 2002 by one Dallas Thompson on Art ...

The Vault is Slate’s history blog. Like us on Facebook, follow us on Twitter @slatevault, and find us on Tumblr. Find out more about what this space is all about here. Eccentric would-be explorer John ...

Have you ever wondered why Santa Claus lives at the North Pole, of all places? The answer might reside in a small urban park that was once a graveyard in Hamilton, Ohio. You will find there the Hollow ...