Windley Key Fossil Reef Geological State Park protects an old quarry cut into fossilized coral reef. The walls show the ancient coral structure clearly, which is a useful reminder that the Keys are not sandy barrier islands but the exposed remains of reef and limestone.
Short trails run through tropical hardwood hammock and around the quarry faces. It is a quick stop, but a good one if you want to understand the ground under your feet before heading back to the living reef offshore.