The paucity of written documentation for these cultures makes for large gaps in our understanding of them. what sorts of information can we obtain about cultures such as these without written texts, and what will we never know?

The answer is: Without any documentation from these societies we can still learn a great deal about their culture by looking at the architecture and bones.

By looking at the architecture of past society, we can guess what that building was being used for and predict the type of behaviors that displayed by past societies.

For example, when we found many buildings that look like an altar, we can infer that this society was really religious and often held a public gathering for some sort of ceremony.

The bones could be used by researchers as a basis to determine the dates when that society exist.