Roads and bridges
Even though the Incas had never heard of the wheel or the horse, they did develop an impressive network of roads that made transportation throughout the empire easier. This network had about 20,000 kilometres of roads (about 5 times the length of Canada). These roads were paved with stones and were used for transporting goods, either on the backs of men or llamas.
The Inca built bridges and tunnels so that the roads could cross difficult terrain like mountains and swamps. The bridges were made of woven vines. The floor of the bridge was made of wood or bamboo boards. To make bridges and tunnels, the Incas borrowed techniques already being used by the peoples they had conquered and put them into practice throughout the empire.
Author: Alexandre Lanoix