The Stronghold (thriller) invites the boys to his house where in a big worry and hurry he tells them the story about Inca civilization, the ruins, which according to some historians were built by Incas, but which, however, could not be erected by Incas given their level of technology. The artist also tells them a legend about a lost city called Paititi, shows them a blurred photo of some unknown ruins in selva and gives them a handwritten map supposed to lead to that place. After some deliberations the guys decide to go to Peru and look for the Inca’s stronghold. Gunnar Ivers
Machu Picchu then crossed a pass and into the Pampaconas Valley where he found more ruins heavily buried in the jungle undergrowth at Espíritu Pampa, which he named "Trombone Pampa". As was the case with Machu Picchu, the site was so heavily overgrown that Bingham could only note a few of the buildings. In 1964, Gene Savoy further explored the ruins at Espiritu Pampa and revealed the full extent of the site, identifying it as Vilcabamba Viejo where the Incas fled after the Spanish drove them from Vitcos. Bingham returned to Machu Picchu in 1912 under the sponsorship of Yale University and