Thus the want to dig stuff up, blow stuff up...........the entrance might be small...........it might be above ground or below ground.....

From A to Z

The Amazon has always been a good place to disappear. Colonel Percy Fawcett, an eccentric British adventurer and surveyor, vanished in 1925 in search of the Lost City of Z, a latter-day El Dorado thought to be somewhere on the Upper Xingu in Mato Grosso. The jungle lived up to its reputation. Fawcett is thought to have misread Manuscript 512, housed at the National Library of Rio De Janeiro by Portuguese explorer (bandeirante) João da Silva Guimarães, who claimed to have visited a ruined city in the sertão (outback or hinterland) of Bahia (not Mato Grosso) in 1753.

In his book The Lost City of Z: A Tale of Deadly Obsession in the Amazon (2009), Michael Grann claims that Fawcett was really onto something. The archaeological site of Kuhikugu on the Xingu shows evidence of defensive ditches, pallisades, huge plazas (one of which is 490 feet across), canals and roads. Other evidence that the Amazon basin wasn’t as wild as it is now comes in the form of work by Alceu Ranzi, a Brazilian geographer, who discovered geoglyphs, roads and large-scale encampments, when flying over the deforested areas of Acre, the lowland Brazilian state which abuts the frontier with Peru.