This is the world's tallest arch, the widely recognized symbol—“The Arch”—of St. Louis, Missouri, and the official centerpiece of the Jefferson National Expansion Memorial, “Gateway to the West,” administered by the National Park Service.

The state of Missouri is home to the biggest arch in the United States and the world: the Gateway Arch in St. Louis. Standing at a magnificent 630 feet (192 meters) tall and 630 feet wide, it is the tallest human-made monument in the Western Hemisphere and the world's tallest stainless steel arch. Designed by the renowned architect Eero Saarinen and completed in 1965, the arch was built to commemorate the westward expansion of the United States and serves as the centerpiece of the Gateway Arch National Park. Visitors can take a unique tram system that travels through the hollow interior of the arch to an observation deck at the very top, offering views that stretch up to 30 miles in every direction across the Mississippi River. Its iconic "catenary" shape is not just an artistic choice but a structural marvel that allows the arch to support its own immense weight without the need for internal scaffolding.