History and culture
Key Largo made the reef a state park
John Pennekamp Coral Reef State Park gives Key Largo the country's first undersea park story.
Key Largo has beaches, boats, and highway-mile-marker charm, but John Pennekamp Coral Reef State Park adds a deeper story.
The park is known as the country’s first undersea park. That matters in a simple way: the main treasure is not only on land. It is the reef, the clear water, the fish, and the idea that an underwater place can be protected for people to see and respect.
The park covers about 70 nautical square miles. Some visitors see the reef from a glass-bottom boat. Others snorkel or dive when weather, water, health, and skill make that a good fit. Even if you stay dry, the park helps explain why the Florida Keys are not just a string of islands. They are tied to a living reef system.
This is a bright story, but it still needs a current check. Wind, visibility, boat schedules, water conditions, and park alerts can change the day.
Before you go, check the park page and match the activity to your group. A reef trip feels better when the plan fits the water, not just the vacation photo in your head.
Where to see it
John Pennekamp Coral Reef State Park in Key Largo. Check Florida State Parks for boat tours, snorkeling, diving, weather, water conditions, and park alerts.
Official sources
Last checked against these sources: July 1, 2026.