After a long walk, your characters decide to enter an apparently abandoned cave and without any special attributes, just a cave.
but, when entering it, an indication of human work begins to appear, it is a hidden mine inside the cave with enough construction to transport large amounts of minerals.
In the center there are three train tracks, which wall lead to the same place, or at least at this point in the mine is where they meet each other, but you can't see the carts by which the mineral can be transported, maybe already they are not in the mine ... or someone is using them.
This map has a 24x40 grid
All variations have a gridded and gridless version.
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