The Gateway Arch, standing at 630 feet, is not only a monument but an iconic symbol of St. Louis, Missouri. It reflects the city's role in the Westward Expansion of the United States during the 19th century. Designed by architect Eero Saarinen and completed in 1965, it is the world's tallest arch and the tallest man-made monument in the Western Hemisphere. Visitors can take a tram ride to the observation area at the top, which offers breathtaking views of the city and the Mississippi River.