The Big Mound Key-Boggess Ridge Archeological District is a historic site near Placida, Florida. It is located southeast of Placida, on Big Mound Key. On December 3, 1990, it was added to the U.S. National Register of Historic Places. Archaeologist George Luer began investigating Big Mound Key after looters used a bulldozer in 1981 to open up a mound in search of Spanish gold. The land had been purchased by the State of Florida in 1978, but little was done to protect the site. After obtaining a grant from the State of Florida, Luer led an intensive excavation of the site from 2008 until 2011.