The Inca road system is an admirable feat of engineering, and it served several important functions for their Empire.
Now primarily a tourist attraction, Inca roads were once the arteries of a mighty Empire. Spanning a the continent lengthwise, the Inca road network covered approximately 22,000 miles of roads and trails with about half of that paved. They built stone surfaced roads where the terrain required it, but merely marked the way and distance on dessert or flat coastal terrain. Many miles of the Inca roads were captured from the civilizations they conquered. Some were built purely for ceremonial purposes, but the primary purpose of the roads was to hold the Empire together by providing vital arteries for communications and troop movements.
The Inca Empire was less than a century old when conquered by the Spanish although Inca civilization before imperial expansion was significantly older. Inca roads had way houses called tampo about every three kilometers, and at each of these was stationed a runner of the chasqui trained to perfectly remember and repeat messages from boyhood. Upon receipt of Imperial communications this runner would run to the next tampo and relay the message. Messages could travel from the Capital at Cuzco to the farthest reaches of the Empire in about one week. For the benefit of the chasqui and other travellers fruit trees were planted along the roads where the terrain was suitable. Larger tampo that were also military storehouses were located at intervals of about one day's travel along the roads. At important points there were storehouses with enough supplies to feed and arm 25,000 troops. Using this system the Emperor could transmit his will and deploy troops rapidly.
Inca civilization was based upon the deification of the Emperor who was said to be the Son of the Sun. It was an autocratic society with an authoritarian structure and a tax system wherein the subjects paid their taxes in the form of labor. All crops belonged to the government, but everyone was fed from imperial storehouses. Working in the fields was one way to pay taxes. Other forms of the labor tax (called the mita) included construction of roads and irrigation canals, claiming new agricultural lands through terracing, building ceremonial sites, working in the gold and silver mines, fighting for the Emperor, and other tasks. Like Charlemagne did to the Saxons, the Inca Emperors transported newly conquered or hostile populations to new locations, and their road system made the implementation of this strategy easier and more effective.
Small streams on the road system were traversed by stone bridges, and large rivers and ravines by long suspended rope bridges. In many places road building consisted largely of building walls to prevent travelers from falling off narrow mountain trails. In other places the roads were wide and paved. The wheel was unknown, so foot traffic and lama trains were all that had to be accommodated. In many places the roads have steps. Although they may appear primitive by modern standards, Inca roads were a miraculous feat of engineering, and the longest road, named the Camino Real by the Spanish conquerors, traverses virtually the entire length north to south of the South American Continent.
Interestingly, a surprising natural feature of the high Andes was a spur to the growth of this amazing Empire. In the high Andes the night/day cycle goes from freezing to hot and dry. Potatoes left in this climate will be alternately frozen and then dried, thus freeze dried and preserved. Several varieties of maize including popcorn were also grown and stored. Corn alone was the basis of many American civilizations, and with the addition of freeze dried potatoes the Inca were well supplied indeed. In a climate subject to periodic drought this stored food supply was a crucial factor in Imperial growth by freeing labor for construction projects even in drought years. The freeze dried potatoes were ground into a flour for use as a staple food. The largest stores were held in or near the Capitol at Cuzco which the Inca referred to as “the navel of the world”.
Llamas, guinea pigs, and dogs were domestic animals all raised for the purpose of adding meat to their diet, but the llama was the main animal for carrying loads. Transportation on Inca roads coupled with food storage built the Inca Empire, but Spanish sail, navigation, and military technologies coupled with a lust for gold (which the Inca had in plenty) and diseases for which the indigenous people had no immunity led to its demise.
