Inca road system, Ancient road network across the Andes Mountains, South America

The Inca road system, called Qhapaq Ñan ("royal road") in Quechua, was a planned network of formal roads about 40,000 km long, with two north-south axes: one inland along the mountains and one along the coast. Builders paved sections where needed, cut stairways to gain elevation, and added bridges, retaining walls and drainage channels. Surviving stretches appear as straight paths of compacted tan earth running between low walls of stacked brown, grey and tan stones.

Pre-Inca cultures such as the Wari (800–1200 AD) and Tiwanaku built earlier roads that the Incas took over, improved and extended. The large-scale works began by order of the Inca Pachacútec, who according to Juan de Betanzos was already drawing roads and bridges before taking power; his successors continued the task. After the Spanish conquest in the 16th century, Europeans used these routes as strategic paths through the Andes.

The Quechua name Qhapaq Ñan, "royal road", reflects its role for the Sapa Inca and the chasquis, runners who relayed messages between stations along the route. The chronicler Garcilaso de la Vega recorded that Cusco, the hub from which four roads left for the suyus, means "navel of the earth".

The network crosses six countries, and the UNESCO listing covers 274 components, including 137 separately numbered stretches. The best-known remnant is the Inca Trail to Machu Picchu, only a small fraction of the whole. Elsewhere, routes such as the western road follow the foothills near today's Pan-American Highway.

The chasquis were relay runners stationed at short intervals along the roads, passing messages from one station to the next. A 2021 study found that communities living within 20 kilometres of the Inca Road still show higher wages, nutrition and school levels than similar communities farther away.