El Comercio reports that a team of Polish and Peruvian investigators looked specifically at the Intimachay area of Machu Picchu, which contains a structure with a front and side window. The researchers report that Inca astronomers could have watched and tracked a number of astronomical phenomena from the area, including summer and winter solstices and the movement of the moon.
The most interesting thing about the research, perhaps, is the technology used to carry it out. El Comercio reports that the international team used 3D scanning software to analyze the structures and compare their shape and placement with the positions of the stars as would have been seen by the Incas.
Full article: http://www.peruthisweek.com/news-machu-picchu-incas-watched-the-heavens-at-mountaintop-observatories-103470