The Incan ruins at Machu Picchu have been the subject of research and speculation since their rediscovery in 1911. While Peruvians knew about this "Lost City of the Incas" above the Urubamba Valley, they weren't excavated and examined by historians until Hiram Bingham did so in 1911. Ever since then, the tiered stone ruins have been on the radar of historians, anthropologists and tourists alike. Nobody is exactly sure why the Inca people built this architectural wonder, but some theories include use as a destination for religious pilgrimages, a retreat for Incan rulers or as an astronomical observatory.
Whatever its purpose, to view the ruins that sit unseen from below remains one of the truly breathtaking things you can take part in. The three distinct areas constructed in the 1400s (agricultural, urban and religious) are all built to blend seamlessly into the surrounding natural environment. The combination of the history, mystery and natural wonder of Machu Picchu make it one of the new Seven Wonders of the World.