At the Earth's Core (Pellucidar, #1)

At the Earth's Core is a 1914 fantasy novel by American writer Edgar Rice Burroughs, the first in his series about the fictional "hollow earth" land of Pellucidar. It first appeared as a four-part serial in All-Story Weekly from April 4 to 25, 1914. It was first published in book form in hardcover by A. C. McClurg in July, 1922.