Machu Picchu
Machu Picchu is a 15th-century Inca citadel set high in the Andes Mountains of Peru, believed to have been built as a royal estate for Inca emperor Pachacuti.
Built around 1450 CE at an elevation of roughly 7,970 feet, Machu Picchu was abandoned about a century later, likely around the time of the Spanish conquest, though the Spanish never discovered the site themselves.
The citadel remained largely unknown to the outside world until American historian Hiram Bingham brought international attention to it in 1911, though local farmers were already aware of the ruins.
The site's dry-stone construction, built without mortar, remains remarkably intact today. It was named a UNESCO World Heritage Site in 1983 and one of the New Seven Wonders of the World in 2007.