There is an Inca citadel high up in the Cordillera in Peru
Towering over the rest of the surrounding area on a 7,970 feet mountain ridge lie the remains of a 15th-century Inca citadel, commonly referred to as Machu Picchu. The incredible views make it one of the most popular attractions in South America.
The Inca did not have a writing system, so there are no records about what it was used for. Nevertheless, archaeologists believe that emperor Pachacuti built it to use as a retreat.