Fodor's Expert Review Seven Mile Bridge
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. It has 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 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. No cars are allowed on the old bridge today.