Gateway Arch by the numbers

Height: 630 feet

Width: 630 feet

Arch shape: catenary curve

Stairs (not accessible to the public): 1,076

Construction began: Feb. 12, 1963

Construction completed: Oct. 28, 1965

Construction cost: $13 million

Basic materials: steel and concrete; stainless steel outer skin

Architect: Eero Saarinen

Tidbits:

The arch is not rigid. Buffeted by a 20-mph wind, it will sway one-half to 1 inch. In a 150-mph wind, it will sway 18 inches. The arch also is designed to withstand an earthquake.

If you go:

Visitors can also go to the top of the Arch via a tram. Tickets are required, and advanced purchase is recommended at gatewayarch.com.