When I visited Hoover Dam in Nevada it was a late afternoon in November. Although the sun was still out things were becoming shadowy, which added to the drama of the scenery. I had the opportunity to stand on an observation deck with an unobstructed view of the dam. It was so massive that I just stood and stared at it for a long time. This picture shows the shadow of the bypass bridge against the dam. After that I walked on the sidewalk toward Lake Mead and I could see shadows forming there too. Here is some of what I saw.
More shadows can be found here.