The Gateway Arch is the centerpiece of the Jefferson National Expansion Memorial located in St. Louis, Missouri near the start of the Lewis and Clark Expedition.
The Arch, designed by Finnish-American architect Eero Saarinen, stands 630 feet (192 m) tall, and is 630 feet (192 m) at its widest point. The interior of the Arch is hollow and contains a unique transport system leading to an observation deck at the top. The interior of the Arch also contains two emergency stairwells of 1076 steps each, in the event of a need to evacuate the Arch or if a problem develops with the tram system. [ wikipedia link ]
Contributed by Kevin & Stephen L.