When it opened in 1964, the Verrazano-Narrows Bridge was the world’s longest suspension span. The bridge was named after Giovanni da Verrazano. In 1524, he became the first European explorer to sail into New York Harbor. Its 693-foot-tall towers are 1 5/8 inches farther apart at their tops than at their bases because the 4,260-foot-long required engineers to take into the account curvature of the Earth. Each tower weighs 27,000 tons and is held together with three million rivets and one million bolts. Seasonal contractions and expansions of the steel cables cause the double-decked roadway to be 12 feet lower in the summer than in the winter.