Lignumvitae Key Botanical State Park in the middle Florida Keys protects Lignumvitae Key, Shell Key, nearby submerged lands, and part of Lower Matecumbe Key, with access limited to boats to help preserve a fragile landscape. At its heart is a 287-acre island with one of the Keys’ best remaining tropical hardwood hammocks, recognized as a National Natural Landmark in 1968, alongside an aquatic preserve created in 1969. Its forest of about 60 Caribbean-rooted tree and shrub species grows on ancient Key Largo Limestone. The park also preserves mangrove habitat, diverse birdlife, butterflies, and a rare surviving glimpse of the older Florida Keys environment.