Using GIS as a Tool for Analysis and Visualization of High-altitude Sacred Sites in the Peruvian Andes Adina Racoviteanu Adina.Racoviteanu@Colorado.EDU Todd Ackerman todda@Colorado.EDU Mark Williams (markw@snobear.Colorado.EDU) University of Colorado, Boulder Department of Geography, INSTAAR, and NWT LTER Abstract Here we report on the use of the latest geo-visualization tools to understand how and why Incas choose the location of ceremonial sites in Peru, South America. Recent discoveries of high-altitude ceremonial sites in the Andes bring about the question of why these ceremonial sites were located on top of the mountains at altitudes often up to 23,000ft. High-altitude archeologists believe that rituals were meant to appease the “Apus”, or Andean mountain gods, held responsible in Andean beliefs for rain, water sources and fertility of the fields. Other hypotheses suggest that these sites were linked with the expansion of the Inca Empire, and the rituals were performed when a new road was built. This would explain the location of some of the sites close to trans-mountain roads constructed by the Incas. While the rituals themselves seemed to be motivated by natural disasters such as earthquakes and droughts, there is little understanding of how and why the Incas chose their sites at such high elevations. We begin our analysis of the spatial distribution of these high-altitude archaeological sites and sacred mountains using GIS mapping and analysis. Sites were georeferenced on a Global Land One-km Base Elevation (GLOBE) Project DEM for high –elevation areas of Peru. Next, we evaluated the site locations with respect to drainage networks, glacier cover, and proximity to trans-mountain roads. Both elevation and aspect of the mountain terrain were used to determine general patterns of altitude and orientation of the archaeological sites with respect with the two sacred directions in the Andes: East and West (rising and setting point of the sun). An aerial perspective has helped interpreting the archeological sites at Nazca and Macchu Picchu. Here we use the latest geo-visualization techniques to evaluate the ceques lines emerging from the Inca Capital- Cusco to sacred sites of importance for the Incaic cosmology including mountain tops and rivers. A visualization of the sites in three dimensions was conducted using ESRI's ARCGIS package. Using the fly-tool of the ArcScene 3D viewer and analyst, we were able to gain a panoramic view on the location of the sites from different elevations.