13. The Gateway Arch | St. Louis, MO
St. Louis boasts the world’s largest arch, standing at 630 feet tall. This colossal metal structure was built in the mid-20th century to commemorate America’s westward expansion, symbolizing the connection between the East and West and honoring the country’s pioneering spirit. To truly grasp the architectural marvel, obtain a ticket to the Gateway Arch Tram and ascend to the top of the monument.