Lower Matecumbe Key is an island in the Upper Florida Keys. It is located on U.S. 1 between mile markers 75–78. All of the key is within the Village of Islamorada as of November 4, 1997, when it was incorporated.
The island lies to the southwest of Upper Matecumbe Key, and to the northeast of Craig Key.
Local attraction Anne’s Beach is located at mile marker 74 on the oceanside of the roadway.
Lower Matecumbe Key History