The Gateway Arch is a 630-foot (192 m) monument in St. Louis, Missouri, United States. Built with stainless steel and in the form of a weighted catenary arch, it is the world's tallest arch, the tallest man-made monument in the Western Hemisphere, and Missouri's tallest accessible building.
The Gateway Arch is a monument to the westward expansion of the United States, and is officially dedicated to "the American people". The Arch, commonly referred to as "The Gateway to the West" is the centerpiece of Gateway Arch National Park and has become an internationally recognized symbol of St. Louis, as well as a popular tourist destination.
The Arch was designed by Finnish-American architect Eero Saarinen in 1947. It took two years to construct and cost $13 million. The Arch is located at the site where St. Louis was originally founded - on the west bank of the Mississippi River.