Fort Massac was a French colonial and early National-era fort on the Ohio River in Massac County, Illinois, United States. Its site was listed on the National Register of Historic Places in 1971.
Wikipedia https://en.wikipedia.org/wiki/Fort_Massac
Official Website http://dnr.state.il.us/Lands/Landmgt/parks/R5/frmindex.htm
Address (Unnamed Road), 62960, United States
Coordinates 37°8'34.992" N -88°42'42.659" E
