The ruins of Machu Picchu are covered in jungle growth in this 1911 photograph taken when Yale archaeologist Hiram Bingham first came to the site a century ago this week.
Bingham was surprised to find that the ancient Inca sites he visited in Peru, including Machu Picchu, weren't as hidden or deserted as he imagined they would be. (Related: "What Was Machu Picchu For? Top Five Theories Explained.")
"When he climbed the mountain on July 24, 1911, he was very surprised to find an Indian family at the top of the ridge," said Christopher Heaney, a Harrington Doctoral Fellow at the University of Texas at Austin.
In fact, three families were living on the mountain ridge on which Machu Picchu was built. A young boy from one of those families guided Bingham up the rest of the mountain, where he got his first complete glimpse of the 15th-century city that he would later make world famous.
Most of Machu Picchu was covered in jungle vines and trees in 1911, but there were a few sites that the Indian farmers had cleared away to grow crops.
"It was very much a living site, not something lost and dead," said Heaney, who is the author of the book Cradle of Gold: The Story of Hiram Bingham, a Real-Life Indiana Jones, and the Search for Machu Picchu.
(Read more about the 1911 "rediscovery" of Machu Picchu.)