During the war, the city of Rotterdam was totally destroyed. Afterward, it was hastily re-built, and filled with aesthetically lacking concrete structures. In an effort to jazz things up,a group of artists began installing creative art installations throughout the city. The artists, known locally as Kunst en Vaarwerk, or have developed a few influential pop art pieces to liven up Rotterdam. One of which is a massive Polaroid photo total with a giant red pin holding it up. It was hung up in 1981 and led by the artist Hans Citroen. The artwork is intentionally hung up slightly skewed. On the Polaroid,there has been a variety of pictures. Originally it was the deck of a Ship, and as of 2019 it's a cargo crane from the harbor. All images are themed after the Rotterdam Harbor, and as the artist collective all believed that to be Rotterdam's strongest asset.
Source: atlasobscura.com