Answer:
Rope bridges is the answer.
Step-by-step explanation:
Inca Empire, also known as the Incan Empire and the Inka Empire was the largest empire in the pre-Columbian America. Cusco was the most important city since it was the administrative, political, and military center.
Inca rope bridges are suspension bridges over canyons and rivers built by the Inca Empire. They were part of the Inca road system and it's a proof of Inca innovation and engineering and they were very helpful since Inca people didn't use wheeled transport.