Bridges. Ponte Fabricio -- Iron Bridge -- Britannia Bridge -- Garabit Viaduct -- Firth of Forth -- Golden Gate Bridge -- Ponte de Normandie -- Tunnels. Two ancient tunnels -- Hoosac Tunnel -- Thames Tunnel -- Holland Tunnel -- The Channel Tunnel -- The Big Dig -- Dams. Ita Dam -- Hoover Dam -- Aswan High Dam -- Itaipu Dam -- Domes. Pantheon -- Hagia Sophia -- Sehzade Mosque -- St. Peter's Basilica -- Les Invalides -- St. Paul's Cathedral -- United States Capitol -- Astrodome -- Skyscrapers. Reliance Building -- Woolworth Building -- Chrysler Building -- Empire State Building -- John Hancock Building -- World Trade Center -- Sears Tower -- Citigroup Center -- Petronas Towers -- Commerzbank Frankfurt.