Machu Picchu Valley. He organized the 1911 Yale Peruvian Expedition in part to search for the Inca capital, which was thought to be the city of Vitcos. He consulted Carlos Romero, one of the chief historians in Lima who showed him helpful references and Father Antonio de la Calancha’s Chronicle of the Augustinians. In particular, Ramos thought Vitcos was "near a great white rock over a spring of fresh water." Back in Cusco again, Bingham asked planters about the places mentioned by Calancha, particularly along the Urubamba River. According to Bingham, "one old prospector said there were interesting ruins at Machu Picchu,"
Machu Picchu then crossed a pass and into the Pampaconas Valley where he found more ruins heavily buried in the jungle undergrowth at Espíritu Pampa, which he named "Trombone Pampa". As was the case with Machu Picchu, the site was so heavily overgrown that Bingham could only note a few of the buildings. In 1964, Gene Savoy further explored the ruins at Espiritu Pampa and revealed the full extent of the site, identifying it as Vilcabamba Viejo where the Incas fled after the Spanish drove them from Vitcos. Bingham returned to Machu Picchu in 1912 under the sponsorship of Yale University and