Machu Picchu Picchu a "historic sanctuary". In addition to the ruins, the sanctuary includes a large portion of the adjoining region, rich with the flora and fauna of the Peruvian Yungas and Central Andean wet puna ecoregions. In 1983, UNESCO designated Machu Picchu a World Heritage site, describing it as "an absolute masterpiece of architecture and a unique testimony to the Inca civilization". Bingham was a lecturer at Yale University, although not a trained archaeologist. In 1909, returning from the Pan-American Scientific Congress in Santiago, he travelled through Peru and was invited to explore the Inca ruins at Choqquequirau in the Apurímac
Machu Picchu though his statements "were given no importance by the leading citizens." Only later did Bingham learn that Charles Wiener also heard of the ruins at Huayna Picchu and Machu Picchu, but was unable to reach them. Armed with this information the expedition went down the Urubamba River. En route Bingham asked local people to show them Inca ruins, especially any place described as having a white rock over a spring. At Mandor Pampa, Bingham asked farmer and innkeeper Melchor Arteaga if he knew of any nearby ruins. Arteaga said he knew of excellent ruins on the top of Huayna Picchu.