In this image you can see four structures above the Canal: in the foreground, the Hamilton Avenue Bridge; the Brooklyn-Queens Expressway; the 9th Street Bridge; and the Culver Viaduct, which carries the F and G trains. Built in 1927, the Viaduct stands 90 feet above the canal to avoid the need for tunneling under the canal, the 4th Avenue line, and the bedrock of Park Slope heading east. The Smith-9th Streets station, pictured far left, is the highest subway station in the world at 87.5 feet above the canal.