From Wikipedia: In physics and geometry a catenary (US: /ˈkætənɛri/, UK: /kəˈtiːnəri/) is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends.

Well, this doesn't exactly describe the Gateway Arch but it's close enough for this blog.

The Gateway Arch in St. Louis, Missouri was designed in 1947 by Finnish-American architect Eero Saarinen and was built between 1963 and 1965. Saarinen won the commission as a result of a design competition. The competition's judges first narrowed the submissions from 172 to 5. Eero's father Eliel had also submitted a design. When word arrived that the Saarinen entry had made the top 5 it was thought to be Eliel's design. A champagne toast was raised to celebrate. A couple of hours later word arrived that there had been a mistake. It wasn't Eliel's design that had made the top 5, it was Eero's. More champagne flowed!

The Eero design was unanimously selected in the second selection phase. (I'm guessing champagne flowed once again.) 

There's a  viewing platform at the top of the Arch. People arrive there via tram cars. Each tram car has multiple pods that seat 5 people each. Think twice if you're prone to claustrophobia. But if you make it to the top the views over St. Louis and the Mississippi River are quite spectacular. 

This might be a fairly unusual image of the Arch. Most show more of it, if not the entire structure, in all its curvaceous glory. I've chosen here to focus on a detail that only suggests the curvature. You can use your imagination to fill in the blank, or there are a million beautiful images on-line you can easily access.

Some facts about the Arch: 

• 630 feet tall and 630 feet wide at its base
• Tallest structure in Missouri
• Clad in 1/4" stainless steel
• Weighs 43,226 tons
• My copyright is not actually engraved in the Arch