So what you're saying is there was a massive technologically advanced civilisation which didn't build buildings, didn't carve stone, didn't mine or refine metals, didn't deforest, didn't farm, and didn't use oil?
> Terra preta soils are found mainly in the Brazilian Amazon, where Sombroek et al. estimate that they cover at least 0.1–0.3%, or 6,300 to 18,900 square kilometres (2,400 to 7,300 sq mi) of low forested Amazonia; but others estimate this surface at 10.0% or more (twice the area of Great Britain).
