That's an awesome marsh man, I love areas like this that are loaded with memories! We lived near a really large wooded area where I grew up and some of the best (and worst lol) memories are from this type of stuff!
I loved seeing the remnants of a tree fort, brought me back some good memories with that. We built a two story tree fort in a crab apple tree! It was next to a ball field and we often harassed the baseball players by throwing apples at them and then wouldn't move at all for a while hahaha they were very confused. We eventually got caught and they weren't too happy but thankfully let us off with just a stern scolding!
it was pretty cool to see that tree fort too. I remember the trail I walked being really well defined, as we used to walk it past some railroad tracks and then eat MREs from the local surplus stores on a sand beach. The trail hardly was there today - I don't think any kids get out there anymore, lol