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 push the stones up inclines. A few stones have knobs that could have been used to lever them into position; the knobs were generally sanded away, with a few overlooked. The Inca road system included a route to the Machu Picchu region. The people of Machu Picchu were connected to long-distance trade, as shown by non-local artifacts found at the site. For example, Bingham found unmodified obsidian nodules at the entrance gateway. In the 1970s, Burger and Asaro determined that these obsidian samples were from the "Titicaca" or Chivay obsidian source, and that the samples from Machu Picchu showed long-distance