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 found in Cusco and the Temple of the Sun found in Pisac, in having what Bingham described as a "parabolic enclosure wall". The stonework is of ashlar quality. Within the temple is a 1.2 m by 2.7 m rock platform, smooth on top except for a small platform on its southwest quadrant. A "Serpent's Door" faces 340°, or just west of north, opening onto a series of 16 pools, and affording a view of Huana Picchu. The temple also has two trapezoidal windows, one facing 65°, called the "Solstice Window", and the other facing 132°, called the "Qullqa Window". The