Machu Picchu

The Inca citadel built around 1450 AD on a ridge between two mountain peaks at 2,430 metres above the Urubamba River was unknown to the outside world until Hiram Bingham III of Yale University documented it in 1911 -- though local farmers had known of it throughout. UNESCO inscribed it as a World Heritage Site in 1983, Peru declared it a Historical Sanctuary in 1981, and it was voted one of the New Seven Wonders of the World in a 2007 global poll with 100 million votes, receiving 1.5 million visitors annually.