At its peak, the Inca Empire stretched for over 2,500 miles, all connected by paved roads. How did a tiny tribe turn into a mighty empire? And why did they disappear?

The Inca Empire is part of the Super Science Facts series that engages readers in grades 5 to 12 with fun science facts and colorful images on every page to support comprehension. The series covers Physical Science, Life Science and Social Sciences in individual sets. The minimal-text format (1,700 to 2,000 words per book) introduces content vocabulary defined in context and repeated in a glossary.