This is a springtime photo of the famous Gateway Arch in Saint Louis, Missouri. Part of the Jefferson National Expansion Memorial it was designed to reflect St. Louis' role in the westward expansion of the United States in the 19th Century. Towering 630 feet (192 meters) above the mighty Mississippi River, it is the tallest man-made monument in the United States and the tallest stainless steel monument in the world. Construction took 30 months and was completed in October 1965. It is still an engineering masterpiece nearly 50 years after its completion. Visitors can still ride specially constructed tram elevators to the observation area at the arch's peak.