This is one of the highest spots at the Machu Picchu site and has a 360-degree view of mountains and clouds. This is said to be the ritual altar for Inca holy men.
The white clouds wash out the top of this image, but you can peek thru the windows to catch a glimpse of the Andes Mountains. All the stonework we witnessed from Lima to Cusco to Machu Picchu was very precise and detailed.