Tillamook in Oregon is well known as a home of cheese production. It is also home to an airfield that was once a base for naval airship operations. Two massive hangars were built to house the huge airships in the days before they went out of favor as a patrol vehicle. One of them remains and is the home of a museum amongst other things. The other hangar is long gone. However, traces of it remain.
The structure of these large hangars was predominantly wood but there were some concrete elements. Each end of the hangar had huge rolling doors and the posts to support that system were large concrete structures. Meanwhile, the arches along the length of the hangar were rooted in concrete bases. While the wood from the hangar has been taken away, the concrete sections remain. Whether they were too difficult to remove or just not worth the cost, I don’t know. What I do know is that they are still there and other things have moved in to operate within their footprint, in this case a lumber yard.
I include a picture of the remaining hangar for reference so you can see where the various structural elements exist within the finished building in case it is not immediately apparent. When we first passed by this location on a trip about ten years ago, it took me some time to work out what these strange items were.