The explorer had first reached the ancient Incan city on July 24, 1911
Until the archeologist Hiram Bingham came across it on this day, July 24, in 1911, most of the world thought the ancient Incan city of Machu Picchu was lost, as was their capital Vilcabamba. As TIMEreported in 1948, when Bingham returned to Peru to celebrate the opening of a road to the site, which would bear his name, he began by studying old charts and texts, until he was sure that there was an Incan capital city somewhere in the Andes that had never been found by the Spanish invaders. He got a key tip from a local muleteer and, upon climbing Machu Picchu peak, found the lost city hidden under vines.
Of course, the very fact that the muleteer had the tip to offer means that Machu Picchu was never completely lost in the first place. It was just ignored by all but the locals who lived their lives around the site.