Lignumvitae Key Botanical State Park is a Florida State Park located on 280-acre (1 km2) Lignumvitae Key, one mile west of U.S. 1 (Overseas Highway) at mile marker 78.5, and can only be reached by private boat or tour boat.The park was also added to the National Register of Historic Places on February 16, 1999 under the designation of Lignumvitae Key Archeological and Historical District. According to the National Register, it contains 3 historic buildings, 3 structures and 8 objects.