One of the highest in the chain of islands formed of "Key Largo Limestone" over 125,000 years ago. About 5,000 years ago, the water level stabilized and the ancient coral reef crest that remained exposed created the islands known as the Florida Keys. The quarry at Windley Key was active into the 1960s and today stands as a preserved geological treasure. The park offers a rare opportunity to compare coral today with its ancient ancestors. Ranger-Guided Tours available year-round, Friday through Sunday, 10:00 AM & 2:00 PM. Tour fee is $1/person, free admission for children ages 6 and younger. Rangers give tours of the old quarries used by Henry Flagler and the subtropical hardwood hammock. Call (305) 664-2540 for more information.