The Temple of the Three Windows
The windows are a representation of the vision of Andean Cosmology, each window representing a spiritual level: the world above (Hanan Pacha), the world we live in (Kay Pacha), and the underworld (Hurin Pacha). The three windows are the largest found at Machu Picchu.
All Inca constructions had features related to the spiritual world that transcend the purely visible and functional role of the building.
