I have a stashmarker on my map that points me to the cement factory, but when I got there I noticed that the maker was located at a tree. I have gone round that tree a bazillion times ( yes I´m really dizzy now) but I can´t for the life of me find the stash. Here´s a pic to show which one I´m talking about:
[smg id=2048]
If I'm not mistaken, it is under the tree in a tunnel :) Go away from there. It is either to the north (waterside) and look for an entrance or a building you need to go downstairs.