Turtle Mound is a prehistoric archaeological site located 9 miles south of New Smyrna Beach, Florida, on State Road A1A. On September 29, 1970, it was added to the U.S. National Register of Historic Places. It is the largest shell midden on the mainland United States, with an approximate height of 50 feet. The mound extends for over 600 feet along the Indian River shoreline and contains over 35,000 cubic yards of shells.