S1 E4: Next on Episode 4

Aired: 12/8/2015 | 0:00:30 | Promotion
Join a team of laser-scanning experts in the Incan city to answer three main questions. How did the Inca build a city atop a mountain ridge? How were the terraces constructed? How did they supply water to the city? Premieres Wednesday, December 9, 2015 at 10/9c. Check local listings.