Lost for centuries, Peru’s Machu Picchu is now the most famous ruin in South America. It’s also a UNESCO World Heritage Site and one of the New Seven Wonders of the World. But no one knows what it was used for. Here’s some of what we do know about this mysterious mountaintop:
• The Inca empire dominated South America in the 15th and 16th centuries. Historians think the Inca built Machu Picchu at the peak of their powers, but because the empire left no written records, we have no idea how they used the site.
• The site covers five miles on a mountaintop 7,970 feet above sea level. Perched on the eastern slope of the Peruvian Andes, Machu Picchu overlooks the Urubamba River hundreds of feet below.
• The Inca used no mortar in building. Their precise stonework, expert geometry, and interlocking joints in corners and foundations have held the site so secure that neither time nor earthquakes have shaken it loose. The multilevel site includes more than 3,000 stone steps.