In the Andes, the rituals of libation were the most important social practice in the Inka ceremonies, which involved the entire social group starting with the most important as rulers, deities and the “Yllapa” or bodies of the deceased considered as principal. It is in this context that the “Ushnu” was the appropriate setting for such rituals with a leading role, and this was perceived and described subtly Spanish colonial records. The study based on an analysis of historical sources, shows the detailed description of these places and the complexity and multifunctionality of the “Ushnu,” in relation to the rituals of libation and ancestor worship by the Andean societies. It also raises the possibility of using a large number of the “Yllapa Usno” or receptacles for libations that might have a movable character, and every ancestor of every social group had to give theirs.

The proposal in this article is, that the architectural components of the ushnu platform of Huánuco Pampa are spatially associated with the surrounding landscape and that libation rituals were the most important public activity, of this mode, this platform, was built at the center of this settlement and served as planning principle of the Inca administrative-religious center of Huánuco Pampa.

The archaeological site of Huánuco Pampa, one of the best designed Inka tampus in the Central Andes during the expansion of the Tawantinsuyu Empire, shows evidences of significant astronomical alignments associated to main spaces and buildings. They can be observed at the “Ushnu” platform and the “Inkawasi”; among the “Tianas” (stone seats), niches and main doorways of both of the two structures built of fine Inka masonry. These alignments are associated to positions of the Sun in the equinox, zenith, antizenith and solstices; alignments of the Moon in their extreme positions; as well as very specific star positions of Alpha and Beta Centaurus and the Southern Cross. With these evidences, we propose the importance of the use of the Inka Astronomy in the provincial centers.