Filled with amazing full-color images, readers will visit incredible, natural wonders in these pages! Underground Caves dives into the origins, extreme nature, and usages of each cave system. Historical, geographical, and cultural context encourages kids to learn about the unique explorers, plants, and creatures of the caves. Aligned to Common Core standards and correlated to state standards. A&D Xtreme is an imprint of Abdo Publishing, a division of ABDO.