Hola @mountainwashere. Reading this awesome article of yours and your mention of Incan terraces and Inti made me think of this, one of the best classic Andean music albums of all time:

https://www.youtube.com/watch?v=iiAylleR64Y

Perhaps good background music for looking at Peruvian engineering photos and reading your great article?
The first track (0:00) and at 30:21 resonate with me, but the entire album is classic (Inti-Illimani 3 - Canto de Pueblos Andinos Vol. 1  - 1975). 
Give it a listen if you are keen to hear some music that are another cultural output of the Incans.  Thanks for the great article. Cheers!