In mapping environments, the problem occurs when you receive a drawing that has not been properly assigned a coordinate system. Without a proper system assigned it’s nearly impossible to merge data from other systems or view the project in tools like Google Earth. A glance at the coordinates indicate large numbers that should reflect a known system, not random coordinates.
Harvests multiple drawing extents and properties (DWGPROPS), creates output drawings or reports. Export to Google Earth (KML) with preview thumbnail or web ready reports (HTM) and more.
A popular request is to export geometry in a Civil3D drawing to Google Earth in a KML/KMZ format. This post contains details on how to do it, with a step-by-step procedure for Civil3D. For recent versions of Civil3D, you will want to use the EXPORTKML command because it will support the most object types (including AECC objects). However it has some quirks and this procedure may help iron them out.