Any race of extraterrestrial beings that were curious to know what Earth’s mineral content was, would be well served to examine Peru. Geologically speaking, it would be a perfect location to explore to determine the organic and mineral resources earth has to offer.
There is a place in Peru, in the Pisco Valley, called the band of holes. There is a theory that these holes or indentions are natural, not artificially created. The uniformity of the pattern resembles how crops are planted, or roads are scraped or paved. The way they flow across the contours of the valley in a most uniform pattern. This pattern is very reminiscent of having my property aerated.
The band of holes consists of hundreds of holes. Most are only 6 or 7 feet deep. A curious formation that has been there so long even the natives who live there now have forgotten the story of what they were or who dug them.