Seven Mile Bridge, Linking Florida Keys, Marathon, Monroe County, FL
Significance: At the time the Florida East Coast Railway constructed this bridge it was acclaimed as the longest bridge in the world, an engineering marvel. It was the most costly of all Flagler's bridges in the Key West Extension. Since the beginning it has served as the one and only vital link between Miami and Key West. The logistics of assembling labor and materials and overcoming the difficulties presented by deep water, normal tides and hurricanes attest to the engineering and management skills of those connected with its construction.
Survey number: HAER FL-2
Building/structure dates: 1909- 1912 Initial Construction
Building/structure dates: 1938 Subsequent Work