World Map at General Motors Plaza, Detroit, MI
Here's a Google Maps Satellite view of World Map carved in Granite at General Motors Plaza, Detroit, MI (right by the Detroit River). This World Map shows (not visible on Google Maps) General Motors Facility Locations World Wide.
Wait a second! If you think this is cool, then take a look at what folks in Dubai, UAE have done. They have created a World Map out of sand dredged from sea. This world map is a cluster of 300 islands. Here's a Google Earth View of the "World Map" in Dubai, UAE (also view in Google Maps).