Thought of another one, two or three....
When I was a kid, my dad and I would go camping in the NE Georgia mountains which were also being use by the US Army to train soldiers heading off to Vietnam. We would often see convoys driving up to the mountains, which I always thought was cool to see. Once we got up into the mountains on the Forest Service roads we would sometimes have to stop for a US Army road block which just made our camping adventure even more better.
One of the places we would camp was a sorta cleared out area that had fox holes around the perimeter. There was a large pile of saw dust in the middle of the perimeter, and for some reason, there were fired rifle casings in that pile, which I and my friends would dig through to find. Near the clearing was an intersection of Forest Service roads, and at that intersection, was a mortar.

It was huge, at least to a kid, so I always thought it was a 120mm but it might have been a 82mm. It was just sitting there. So odd.
I assume those roads are all closed off decades ago.
Another place we would camp was really back in the mountains along "roads" that were just trails. One road had a small family cemetery where the old coffins had collapsed leaving hollows on the surface. Most the grave markers were either gone, or roughly made from stone, and so weathered to be all but unreadable. However, there was one, very nice granite marker for a woman that had died in the 1920's. I really wondered how often someone would travel to see that grave, and if anyone in the family was still alive to go to that itty, bitty cemetery...
I think it was down the same trail/road, there was a rather large camp site that was used fairly often by hunters. We don't know if they left it on purpose or not, but there was a large cast iron skillet hanging from a tree. We left the skillet and I often wonder if it is still on that tree, and if so, has the tree grown around the skillet....
Fast forwarding a few decades, I was canoe camping in Eastern NC along the Black River. It happened to be Halloween night and a full moon rose above the river. VERY pretty. The land was owned by the Cone family, which made a fortune many decades, well, maybe a century ago, making cotton denim in NC. We had permission to be camping on the land and there was a sugar sand "road" next to where we set up camp. A couple went off exploring and came back to camp to tell us that they had found a small cemetery in the woods. After we all had dinner we went off to find the cemetery which was marked by a street sign of all things.
What was interesting about the cemetery was that it had a cinder block wall around it along with a nice iron gate so someone had had money at some point. The sad thing about the cemetery was one could see the decline in the family over the generations. The earliest grave marker was a tall monument 6-8 feet tall for the couple who begat everyone else buried in the cemetery. The couple were young adults in the US Civil War and died in the late 1800s. As the generation's died off, the monuments got smaller and less expensive, until the last burials were simply pauper markers. Same question as the cemetery we found in the mountains, how many people, if any, ever visit that cemetery....
Later,
Dan