Once again, simply stated:
“Of several acceptable explanations for a phenomenon, the simplest is preferable, provided that it takes all circumstances into account.” - Occam's Razor
In other words, the simplest explanation is probably the best: If they can only be seen from the air, then to have made them, their makers would have had to be able to view them from the air. Like it or not, and as upsetting to your preconceptions as it may be, no other conclusion is sufficiently rational to pass empirical muster. Sorry.
The fact that 1st World (intellectually Eurocentrically biased) historians record no manned balloon flights until the 1780's just IS NOT GERMAINE. Read the Vedanta or other histories from non euro-centric sources and then just get use to the notion that history as Americans learn it is false and misleading, and induces closed-mindedness rather than wonder. - JWT
"The bizarre Nazca Lines were created thousands of years ago (between 200BC and 600AD) . . . the images are so large that they couldn’t have seen them without some sort of aircraft . . . "
EXPLAIN THIS, THEN, MY FRIENDS. - the Dalphe