6 Best Sights in Marathon, The Florida Keys

This isn't your typical large-city aquarium. It’s more hands-on and personal, and it's all outdoors with several tiki huts to house the encounters and provide shade as you explore, rain or shine. Plan to spend at least two to three hours here. You’ll find a 200,000-gallon aquarium and plenty of marine encounters (extra cost), as well as guided tours, viewing areas, and a predator tank. The Coral Reef encounter ($95 snorkel, $130 regulator) lets you dive without hearing the theme from Jaws in your head (although you can see several sharks on the other side of the glass). Touch tanks have unique critters like slipper lobsters. Hungry? The on-site Eagle Ray Café serves up wings, fish tacos, salads, burgers, and more. Note that general admission is required, even if you've signed up for a marine encounter.

This is one of the most photographed images in the Keys. Actually measuring slightly less than 7 miles, it connects the Middle and Lower Keys and is believed to be the world's longest segmental bridge, with 39 expansion joints separating its various concrete sections. Each April, runners gather in Marathon for the annual Seven Mile Bridge Run.

The expanse running parallel to the Seven Mile Bridge is what remains of the Old Seven Mile Bridge, an engineering and architectural marvel in its day that's now on the National Register of Historic Places. Once proclaimed the Eighth Wonder of the World, it rested on a record 546 concrete piers. A $44 million renovation, begun in 2017, is part of a 30-year, $77-million restoration and maintenance agreement between the Keys' Monroe County, Marathon municipal officials, and the Florida Department of Transportation. No cars are allowed on the old bridge, but the oft-photographed, 2.2-mile span is open to pedestrians and serves as the gateway to historic Pigeon Key, an islet nestled beneath the “Old Seven” that was once home to about 400 workers constructing the railroad. 

One of the best beaches in the Keys has shaded picnic areas overlooking a coconut palm–lined grassy stretch and the Atlantic. Roped-off areas allow swimmers, boaters, and windsurfers to share the narrow cove. Facilities include grills, a large playground, a pier, a volleyball court, and a paved, lighted bike path off the Overseas Highway. Sunday afternoons draw lots of local families toting coolers. The park is accessible for those with disabilities and allows leashed pets. Turn east at the traffic light in Marathon and follow signs to the end; parking is payable at a kiosk with credit card only. Amenities: showers; toilets; parking (paid). Best for: swimming; windsurfing.

Tucked away from the highway behind a stand of trees, Crane Point is part of a 63-acre tract that contains the last-known undisturbed thatch-palm hammock. The facility includes the Museum of Natural History of the Florida Keys, which has displays about local wildlife, a seashell exhibit, and a marine-life display that makes you feel like you're at the bottom of the sea. Kids love the replica 17th-century galleon; the pirate dress-up room; and the re-created Cracker House filled with insects, sea-turtle exhibits, and children's activities. On the 1-mile loop trail, visit the Laura Quinn Wild Bird Center and the remnants of a Bahamian village, site of the restored George Adderly House. It is the oldest surviving example of Bahamian tabby (a concrete-like material created from sand and seashells) construction outside Key West. A boardwalk crosses wetlands, rivers, and mangroves before ending at Adderly Village. From November to Easter, docent-led tours are available. Bring good walking shoes and bug repellent.

There's much to like about this 5-acre island under the Old Seven Mile Bridge. You might even recognize it from a season finale of the TV show The Amazing Race. You can reach it via a restored train that departs from the gift shop, which is in a trailer at Mile Marker 47.5. Once there, tour the island on your own, or join a guided tour to explore the buildings that formed the early-20th-century work camp for the Overseas Railroad, which linked the mainland to Key West in 1912. Later, the island became a fish camp, a state park, and then government-administration headquarters. Exhibits in a small museum recall the history of the Keys, the railroad, and railroad baron Henry M. Flagler. The train ride with tour lasts two hours. Bring your own snorkel gear and dive flag and you can snorkel right from the shore; pack a picnic lunch, too.

Each year, more than 100 injured creatures are admitted to the world's first state-certified veterinary hospital for sea turtles. Guided 90-minute tours take you into recovery and surgical areas. In the "hospital bed" tanks, you can see recovering patients and others that are permanent residents due to their injuries. After the tour, you can feed some of the residents. Call ahead—space is limited and tours are sometimes canceled due to medical emergencies. The turtle ambulance out front makes for a memorable souvenir photo.