The Gateway Arch in St. Louis celebrates its 50th birthday on Wednesday. Created to memorialize the United States' westward expansion, the monument was completed on Oct. 28, 1965, and soon became a popular place for rallies, sightseeing and dangerous stunts.
Here are a few obscure facts about the stainless steel structure.
Standing at 630 feet -- or 63 stories -- the arch is the tallest monument in the Western Hemisphere and the tallest accessible building in Missouri.
The winning design for the monument was selected from a national competition in 1947. Among the 171 losing entries figured a building-sized globe of the Earth, a giant statue of Old Man River, and a pyramid.
The underground visitor center was completed in June of 1967 and the north tram to the top began running in July of that year. The south tram followed in May 1968. When both trams are running, they depart every five minutes and can each carry up to 240 passengers.
Conrad Wirth joked that he waited two decades to visit the man-made wonder because "there was no more tax money" for the trip.
Although the arch doesn't move under regular weather conditions, it is designed to sway as much as 18 inches and can withstand an earthquake. The structure is so stable that 50 mph winds barely move the top 1.5 inches from its center.
The idea of building a memorial to honor Jefferson's championing of the westward expansion was first introduced in the 1930s. The 91-acre monument also includes the Old Courthouse and Luther Ely Smith Square.
In December 1992 John Vincent pleaded guilty to two misdemeanor charges and agreed to cooperate in the prosecution of two men who photographed his jump from the monument two months prior. Twelve years before he successfully parachuted from the arch, a 33-year-old man died while attempting to do the same.
The $380 million venture began in 2013 and will include the creation of a new museum and the restoration of the arch's surroundings.