Having visited Cuzco and Pachacamac, I have covered some inscribed areas of Qhapaq Ñan. However, the site that informed me the most about the historic route was Raqchi, a primary point on the Andean Road System.
Raqchi-Qquea Segment (QÑ-CD-064, QÑ-CD-065)

Raqchi Archaeological Park is an important stopping point along Qhapaq Nan, this can be concluded based on its strategic location, temple, storehouses, and lodging. The partially ruined site and surrounding landscape is striking. An artificial wetland surround part of the site and the various structures are at least peculiar in their uniqueness. During my visit, Raqchi was merely a stopping point on the road from Cuzco to Puno. I could not have been more pleased, this pit-stop was well worth the time. The number of storehouses was surprising. The Wiraqocha Temple is one of the largest Inca structures still standing.
Associated with the road: "Among the archaeological evidence the Wiraqocha Temple stands out; houses, deposits of 155 circular qolqas, water fountains, channels, and an artificial lagoon, a tambo, Inca terraces and a 4,000-metres long linear fortress system that encircles the monumental area where the main temple is." - Nomination File
The Archaeological site of Chaskiwaisi-Tambo is only a short walk away, though its not marked on Google Maps, its visible using Satellite (West from the Iglesia de Raqchi).
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