Constructed between 1963 to 1965, and officially opened on June 10, 1967, the Gateway Arch is a monument to westward expansion and an icon of St. Louis, Missouri. At 630 ft. tall, the Gateway Arch is the centerpiece of the Jefferson National Expansion Memorial, which also features the Old Courthouse. Overlooking downtown St. Louis and the Mississippi River, the observation deck of the Gateway Arch offers some of the most incredible views of the surrounding area.