(Florida)
Lignumvitae Key Botanical State Park is a Florida State Park consisting of Lignumvitae Key, Shell Key, surrounding submerged lands, and a parcel at the northern end of Lower Matecumbe Key. The islands are located one mile west of U.S. 1 at mile marker 78.5, and can be reached only by private boat or tour boat. (Ref: https://en.wikipedia.org/wiki/Lignumvitae_Key_Botanical_State_Park)