Pellucidar

Edgar Rice Burroughs's 1915 adventure novel Pellucidar is a sequel to At the Earth's Core, following David Innes in a prehistoric world at the earth's center, where he faces reptilian Mahars, savage Sagoths, and the treachery of Hooja the Sly One.

Public domain in the US. From Project Gutenberg.

Topic

Historical and Classical Fiction›Classic science fiction and fantasy›Lost worlds, hidden lands, and prehistoric tales›Journeys inside the earth

Reader

Teens›Historical and Classical Fiction›Classic science fiction and fantasy›Lost worlds, hidden lands, and prehistoric tales