Choquequirao to Machu Picchu at the speed of light: visual signaling among the Incas

Research confirms the existence of an Inca visual signaling system, linking Choquequirao and Machu Picchu through inter-visible stations. This system used smoke by day and fire at night to rapidly relay alarms over long distances, staffed by young 'chasqui' runners. The study validates a historical account by Garcilaso de la Vega, suggesting this was part of a broader empire-wide network for communication during insurrections or invasions.

Lee, V. (2010). Choquequirao to Machu Picchu at the speed of light: visual signaling among the Incas. Ñawpa Pacha, 30(1), 1–23. https://doi.org/10.1179/naw.2010.30.1.1