Silver is the tears of the Moon

The Inka did not have a written language, but used oral traditions to pass their knowledge and history to the next generation.  But one should not discount their culture or their understanding of how the world works.  Quipus are called talking knots.  They are the recording devices of the Inka.

A quipu usually consisted of colored, spun, and plied thread or strings from llama or alpaca hair.
It could also be made of cotton cords. For the Inca, the system aided in collecting data and keeping records, ranging from monitoring tax obligations, properly collecting census records, calendrical information, and military organization.The cords contained numeric and other values encoded by knots in base ten positional system. A quipu could have only a few or up to 2,000 cords. The configuration of the quipus have also been 'compared to string mops.' Archaeological evidence has also shown a use of finely carved wood as a supplemental, and perhaps more sturdy, base on which the color-coordinated cords would be attached.

The Inka also invested in their communities.  Each community had three areas:  the agricultural, urban and religious. Quarried stones from other mountains were dragged for miles to be used for religious temples and palaces for their kings.  They remind me of the terraces of southern China.