Seven Mile Bridge

Overview

Seven Mile Bridge is the crown jewel of the Overseas Highway, linking Knight’s Key (Marathon) to Little Duck Key over nearly seven miles of turquoise water. You drive the modern concrete arc while the historic “Old Seven” runs alongside—a photogenic duo that defines the Keys’ road‑trip vibe.

What You’ll See

Expect endless water views and that signature central “hump,” which gives boats 65 feet of clearance. Winds can be brisk, the sun is relentless, and the vistas are wide‑open—bring water and sun protection. Keep an eye out for seabirds and passing marine life in the shallows.

Old vs. New

The current road bridge opened in 1982. Beside it, the original Flagler‑era railroad bridge (1912) survived the 1935 hurricane, was converted for cars, and now lives on as “Old Seven.” A restored 2.2‑mile section reopened in January 2022, letting walkers and cyclists reach Pigeon Key.

How to Visit (and Where to Park)

You can’t stop, walk, or bike on the new bridge—Florida law only allows stopping for emergencies. For a stroll over the water, use the Old Seven entrance on the Marathon side; there’s a small parking lot (about 35 spaces) and picnic tables but no restrooms or water. On the Lower Keys side, Little Duck Key’s Veterans Memorial Park (open daily 7:30 a.m.–sunset) offers views, with restrooms currently handled by porta‑potties and no fresh water at the adjacent fishing pier area. Pigeon Key has restrooms and water refills only with paid admission during operating hours.

Best Time to Visit

Sunrise and sunset bring the best light and cooler temps. Go early if you want a parking spot at the Marathon‑side lot. Weekdays usually mean lighter traffic. In April, the annual Seven Mile Bridge Run briefly closes the bridge on a Saturday morning—plan around it. During hurricane season, monitor advisories; this stretch is very exposed.

A Bit of Backstory

Built 1909–1912 for Henry Flagler’s Overseas Railroad, the original bridge was later adapted for automobiles after the 1935 Labor Day Hurricane. The modern replacement was constructed 1978–1982. Today, Old Seven’s pedestrian span is both a walk through history and the most enjoyable way to linger over these views.

Film Cred

If the scenery feels familiar, it probably is—this bridge has starred in big‑screen action and TV, cementing its legend as the Keys’ most iconic drive.