What is considered the greatest example of Incan engineering?

The road network

what are all the ancwers

yeah I need to know.

I still don't know, someone pls help

i got the answers
The road network.
They forced conquered people to use their language.
The inca cut strips of level land called terraces into hillsides.
Lower ranking nobility held government positions.
textiles. 100%

Tysm!! I couldn't find any answers for like 15 minutes you're a life saver.

np my love

yo thanks man

there's a 5th one