Books like At the Earth's Core

At the Earth's Core by Edgar Rice Burroughs Cutting through the earth in an extraordinary burrowing device, David Innes and Abner Perry fear they may be incinerated in the planet's fiery core. Instead, they come upon Pellucidar - a savage, primordial world hidden several hundred miles beneath the earth's crust. There in an eerie, subterranean realm of vast oceans, lush jungles, and eternal noon, they encounter primitive humans and their beautiful, courageous queen, Dian.