An aerial photograph of Monte Sierpe taken by Robert Shippee and published by the National Geographic Society in 1933 (photo reproduced courtesy of the American Natural History Museum; AMNH Library negative no. 334709). Credit: Robert Shippee, National Geographic Society Key Points: In southern Peru's Pisco Valley, Monte Sierpe -- also known as the "Band of Holes" -- features thousands of perfectly aligned circular pits whose true purpose has long puzzled scientists. New research combining