I've found the remains of several stills out in the Florida woods. Usually near a stream or spring. These seemed older but stills were pretty common in the Florida woods well into the 50s.

I've also come across several pot fields. One was still in production. I would be leery about exploring near pot fields now but back in the day wilderness cultivators were a peace-loving breed. As long as I didn't mess with their crop everything was cool. Getting too close now might get you shot.

Once I found some aircraft parts that had a story about an airplane that went down in the 30s associated with them. They went down in the sticks and it took weeks for them to find the two survivors. Story was a local swamp rat/ trapper/ gator hunter type, found them and led them out.

One trip we came across a section of tiny light-gauge railroad track that led to a small lumber mill. It was set up in the 20s and was abandoned in the early 30s according to the ranger we asked.

Hard to find anywhere where people haven't been and left marks. Recently, in the last couple of decades, GPS mapping of the amazon rain forest showed that the regular spacing of groves of fruit trees was a man-made and a remnant of earlier tribes. They lived nomadic lives traveling in large circuits hunting, gathering, and living off small clusters of select fruit trees.