There is a lot to see out on the ocean and gulf as one walks the Old Span of the Seven Mile Bridge. You can find all sorts of neat historic items if you keep an eye down on the pavement. The Geodetic Marker is used as part of the GPS system. This marker is part of a network of survey control marks that act as physical reference points.
Sometimes the parking lot there at the base of the Seven Mile Bridge gets filled up. There will be four or five cars waiting in line for the next spot. It is very easy to park on The Other Side of the highway and take the nice walk way path up to the bridge entrance. It is legal to park in the grass area next to the highway directly perpendicular to the sunset grill, next to Knights Key campground. It is easy and faster, just turn into Knights Key and park on the right.
47000 Overseas Highway
Marathon FL 33050
Related: marathon bridge park