Qhapaq Ñan

Here is the link to the American Indian museum's exhibit on the Inca road system running throughout the Andes.  The exhibit will be in DC through 2018, I believe, so catch it if you're there.  In the meanwhile, this website does a great job covering the content of the exhibit, from the origins of Andean empires through to the modern day customs of indigenous people in Peru and Bolivia.  Here's a cool video about a rope bridge built in the Inca style.