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 prevent it from running down the mountain. Similar layering protected the large city center from flooding. Multiple canals and reserves provide water throughout the city that could be supplied to the terraces for irrigation and to prevent erosion and flooding. The Incas never used wheels in a practical way, although their use in toys shows that they knew the principle. The use of wheels in engineering may have been limited due to the lack of strong draft animals, steep terrain and dense vegetation. The approach to moving and placing the enormous stones remains uncertain, probably involving hundreds of men to