The Smoky God, or, a Voyage to the Inner World (1908) by Willis George Emerson is a fictionalized "true account" of Olaf Jansen, a Norwegian sailor who claimed to have navigated through an opening at the North Pole into the hollow interior of the Earth. Inside, Jansen discovered a technologically advanced civilization of giants and a central, "smoky" sun. The book is considered a cornerstone of Hollow Earth theory literature, blending adventure with metaphysical speculation about a lost paradise.