The Inca city is named Machu Picchu

What actually happened

Historian Donato Amado Gonzales of Peru's Ministry of Culture and archaeologist Brian Bauer of the University of Illinois Chicago traced how the name stuck. Bingham heard several names when he arrived, wrote 'Machu Picchu' on his sketch because that was the mountain a local landowner's son pointed to, and the label he happened to record became the one printed on every map and ticket for the next century.

The older sources tell a different story. Documents from the late sixteenth and early seventeenth centuries, plus an 1874 atlas, refer to the built site as Huayna Picchu or Picchu, never Machu Picchu. In Quechua, 'machu' means old and 'huayna' means young, and the two peaks flanking the ruins are named accordingly; the city sits below the younger one.

The authors are careful about what this does and does not claim. It does not propose renaming the World Heritage site, which would be impractical after a century of global fame. It documents that the name the world uses is not the name the builders used, which is a real and citable correction to a fact stated flatly in textbooks, and a reminder of how much early archaeology depended on a single explorer's hurried notes.