Evaluation of the use of symbolic solar lighting in Inca sacred sites: Ingapirca archaeological complex

Abstract

The use of solar lighting in Inca sacred sites has been the subject of growing interest. The Ingapirca Archaeological Complex, recognized as a World Heritage Site, still presents interpretive challenges regarding its lighting design. This research evaluated how symbolic solar lighting influenced its architecture and what the combined contributions of the Cañari and Inca cultures were. An architectural and astronomical analysis of the complex was carried out using 2D drawing tools, 3D modeling, and solar simulations, focusing on key dates. The results were compared with historical sources and ethnographic studies. It was identified that the main structures of Ingapirca are aligned with the sunrise and sunset during the solstices, rather than the equinoxes, as previous studies had indicated. The solar illumination highlighted ceremonial elements, reinforcing their symbolic and spiritual significance. This evidence points to intentional architectural planning linked to the Cañari-Inca worldview. In conclusion, solar illumination at Ingapirca not only served a practical function, but also a ritual and symbolic one, demonstrating the integration of astronomy, architecture, and spirituality at the sacred sites of both cultures.