One thing to note is that you should set up a cache_store that works for you. The default store is disk storage, which might slow down accesses if you put lots of objects in your cache. Disk storage is slow to access, anyway.
As I document in my new book "The Lost City of Z: A Tale of Deadly Obsession in the Amazon," even today parts of the Amazon--a wilderness area virtually the size of the continental United States--remain unknown. The Brazilian government estimates that there are more than sixty tribes that are secluded in the jungle.
The dispute over the photographs stemmed from confusion over the meaning of "uncontacted," as these groups are commonly designated. Though Meirelles had never said the tribe was unknown, many in the press had initially portrayed the group as such.
But that did not make the photographs "fakes" or a "hoax." The reason these tribes are classified as "uncontacted" is because they have retreated into the jungle and consciously avoided any interaction with settlers--an interaction that has frequently led to the extinction of Amazonian tribes.