Gateway arch is the tallest arch monument in U.S. It was built to commemorate the Westward expansion of United Sates. The construction of gateway arch started in 1963 and completed in 1965. This arch was designed by Finnish-American architect Eero Saarinen. Today this monument attractions around 4 million visitors every year.
Gateway arch was assembled of 142 different sections of 12 foot long pre-fabricated steel. This arch contains 23570 tons of concrete and 1957 tons of steel. This hollow arch monument contains a unique tram system that takes visitors to top of the arch. The observation deck of gateway arch can hold 160 visitors at a time, offers view up to 30 miles in all direction.