South America was a major settlement location for the Anunnaki.

South America was Ninurta/Michael/Ares/Viracocha's territory.

He had a very large mining operation that operated there.

Most of the areas that are now deserts in South America were once the locations of major settlements that got destroyed during the reclaiming of Earth after Marduk/Ra/Thor/Lucifer's rebellion.

There's a lot of ancient stuff down there.

The Amazon was once host to a massive civilization after the Fall of Atlantis, when many of the Survivors fled there. The Poseidon line of Kings actually ruled the area after the Flood, one of the few surviving demigod bloodlines that were descended from Odin/Ea/Ptah/Poseidon himself, the creator of Earth and humanity.

Sadly that bloodline never recovered after the Flood of Noah.