It was 100 years ago today — July 24 — that the Inca settlement of Machu Picchu was brought back to light.

The 15th Century site, located above Peru’s Urubamba Valley, was abandoned during the Spanish Conquest and forgotten.

Then in 1911, an expedition led by Yale professor Hiram Bingham III discovered the overgrown ruins.

It is now a popular tourist destination and United Nations World Heritage site.

For cool old photos of Machu Picchu shortly after it was found, check out this National Geographic gallery .