What do you suppose these were created for?

I am really interested in exploring the language involved that is based on fact, as well, such as:

There are straight lines extending for __?__ miles in various (every?) direction.

Many of them are depictions of animals.

They are in Peru.

They can only be seen (at least in their entirety) from the sky.

They are __?__ years old.

Please respond by separating your comments into the categories of "I think..." and "Known FACT" so we can discuss them freely, which is so much fun, , but also keep actual known facts separate, so those facts can be explored for additional truths revealed via multidimensional language.