Think what an awe-some experience it would have been for these Amazonians to step out from the jungle canopy into one of their clearings & see the sky overhead. I vote for a religious significance to the clearings.

I wonder at the nature of these roads. The Amazon has always had one definitive road: the Amazon itself, the unique transport system and treeless zone as far as I know. Actually reaching through the tree canopy would be difficult, but if these ancient roads did, they would become the closest things to tributaries of The River in the whole continent.