In 1911, Yale archaeologist Hiram Bingham and a small team of seven set out in Peru to uncover the lost city of Vilcabamba but were quickly led to one of the world's most fascinating sites. The expedition team met Melchor Arteaga, a local farmer, on their trip from Zuzco, who told tales of the "old mountain" ruins known as Machu Picchu - this would eventually prove to be the "Lost City of the Incas." It dates back to at least the 14th century and is today regarded as a Modern World Wonder. Even with cutting-edge technology, scientists need clarification on how the Incas created their city without using steel, masonry, or wheels.