Astronomy in the Andes was well developed by the time the Spaniards arrived in the Inca Empire. This was due in large to the accumulation of knowledge through observations made by the many civilizations preceding the Incas. Astronomy was not simply observing and understanding celestial movement, however, as it was integrally woven into the very fabric of Andean existence throughout myth, cosmology, and culture, playing an important role in daily life. The Incas were a Sun-worshipping people and their emperor was said to be “the son of the Sun.” Their cosmology begins with the primordial rising of the Sun, and also that of the Moon. In their astronomy they were aware of many stars and planets and paid particular attention to the Milky Way and the Pleiades. In a practical sense this knowledge was put to work via horizon astronomy as the Incas marked the passage of sunrises and sunsets on their horizons in order to keep time for agriculture and religion. Ultimately, celestial alignments and effects of light and shadow were integrated into their temples and huacas, as well as with other constructs such as solar pillars built more specifically for astronomical purposes. This presentation will explore aspects of the fascinating astronomy of the Inca Empire.