Over the structure, the ancient Teotihuacanos finished their pyramid with lime plaster imported from surrounding areas, on which they painted brilliantly colored murals.

[citation needed] The pyramid was built on a carefully selected spot, from where it was possible to align it both to the prominent Cerro Gordo to the north and, in perpendicular directions, to sunrises and sunsets on specific dates, recorded by a number of architectural orientations in Mesoamerica.

The tunnels underneath the pyramid gleaned pieces of pottery, hearths, and other meticulously made artifacts from other cultures that showed evidence elsewhere in Teotihuacan.

Various sources point to different theories of interpretations for why the Pyramid of the Sun was built and what the cave systems underneath it truly mean according to the Teotihuacan people and culture.

[citation needed] “Since skeletal remains and charcoal are absent in the cave, owing to ancient vandalism, it is impossible to date the earliest use of the place for ritual purposes or for rites of passage.

In view of the position of the pyramid over the grotto, it would seem that the cave was the focal point and not an accidental coincidence, and that it may have determined the site for the construction of a primitive place of worship and then for the pyramid.”.

[10] The Pyramid of the Sun, built on top of the holy cave described in the excavation above, became a focal point for society as it was located on the Street of the Dead.

More importantly than its physical location, the city layout of Teotihuacan incorporated alignments dictated by the astronomically significant orientation of the Pyramid of the Sun.

The peak of the pyramid was constructed to align with the horizon in order to serve as a natural marker of the sun's position on the Aztec quarter days of the year.

A unique historical artifact discovered near the foot of the pyramid at the end of the nineteenth century was the Teotihuacan Ocelot, which is now in the British Museum's collection.