Pittsburgh Landscape is a 1954 painted steel abstract sculpture, by David Smith. It is in the Hirshhorn Museum and Sculpture Garden.

https://en.wikipedia.org/wiki/Pittsburgh_Landscape

Pittsburgh Landscape

Sunset Song

Monsoon Drift is an abstract steel sculpture by English sculptor Anthony Caro, from 1975. It is located in the Hirshhorn Museum and Sculpture Garden, in Washington, D.C. In 1973, he salvaged rolled steel material, at the Consett steel mills, County Durham, to later use in his sculptures.

https://en.wikipedia.org/wiki/Monsoon_Drift

Lunar Bird