Knotted strings were used to communicate across its extensive road system.
This empire's society was strictly divided into an upper caste called hanan and a lower caste called hurin. It was divided into four provinces led by apos.  Men in this empire were required to farm for 65 days per year and spend the rest on public service. This empire was built around clans called (*) ayllus [EYE-loos]. Runners trekked 200 miles a day in this empire to share messages. Knotted strings were used to communicate across its extensive road system. This sun-worshipping empire used alpacas and llamas as their only beasts of burden. For 10 points, name this empire that constructed Machu Picchu, which was centered in pre-colonial Peru.
This empire's society was strictly divided into an upper caste called hanan and a lower caste called hurin.
Incan Empire