Picnic area at the Old 7 Mile Bridge

The Old 7 Mile Bridge offers a truly unique hiking experience, allowing you to walk across the shimmering waters where the Gulf of Mexico meets the Atlantic Ocean. This easy 4.3-mile (6.9 km) out-and-back route, with a minimal 11 feet (3 metres) of elevation gain, takes about 1 hour and 43 minutes to complete. The paved, flat surface makes it accessible for everyone, and you'll be treated to expansive, open views of the sea and sky, often spotting marine life like rays and sea turtles below.

Planning your visit is straightforward, but remember there's no shade on the bridge, so come prepared with plenty of water, sunscreen, and a hat. Parking is available at the Marathon trailhead, but it can get busy, so an early start is recommended, especially if you want to avoid crowds and the strongest sun. The trail is open year-round, with mornings and late afternoons offering the most comfortable temperatures and beautiful light.

This isn't just a scenic walk; it's a journey through history. The Old 7 Mile Bridge was originally part of Henry Flagler's ambitious Florida Keys Over-Sea Railroad and later served as a vital automotive link to Key West. The restored 2.2-mile section leads directly to Pigeon Key, a small historic island that once housed the railroad workers, adding a fascinating cultural layer to your hike.