When man started to explore the seas, they were confronted with a few problems. During nighttime it was almost impossible to find the way back to land. When they did find land, there was no warning for dangerous areas in the sea. From that time they started to make fires on the coasts during the night. These fires made it possible to navigate home or warned for possible danger. During the centuries, these fires were replaced by alternative light sources to the present day electrical lighthouses. Challenge closed November 21, 2007. http://sketchup3dchallenge.blogspot.com/search?updated-min=2007-01-01T00%3A...