Railroad Car Barn

Historical marker location:

5717 Main St, Sylvania, Ohio

( Marker can be reached from Main Street.)

The Great Serpent Mound, located in Adams County, Ohio, is a prehistoric effigy mound in the shape of a serpent that is more than 1,300 feet long. It is one of the largest effigy mounds in the world and is estimated to have been built by the Adena culture more than 1,000 years ago.