If you can't find what you want in all the CC3 assets you have, you can always import third party assets. There's a list of commonly used ones here:

https://forum.profantasy.com/discussion/10443/free-symbols-artwork

I can't say which of them, if any, will have a furnace in them, but other people might be able to help you there.

Height in a CC3 map is always an illusion. We don't currently have any heightmap features in CC3. Automatic roof shading is achieved by a specialised normal map applied to each building the moment it is placed in the map.

CC3 normal maps are linked with the symbol file in the symbol graphics folder, and only contain information about how steep the roof is, and which direction it is facing relative to the sun as blue and red components.

The connecting cliff symbols have normal maps that function in the same way, which is why they look darker on the face away from the global sun once they are pasted into the map. However, connecting symbols don't scale - as you have already discovered.

If you want to make the connecting cliff symbols bigger you have to draw the line of cliffs at the default scale, and then scale the whole thing up as one long snake of cliff symbols, which is easier to do if you group them first. That can still be tricky, though, because it requires that you can draw a miniature version of the cliff line by eye, perhaps to one side of the map.

Alternative methods that you haven't already tried out are a bit more complicated. You could make your own relief shading sheet like this one I did for a city on a very steep island city, lit from the south east.

But that requires that you have an eye to see where the shadow needs to be in the first place. All good if you do, but if you can't see it in your imagination first I don't recommend it.

Another hand drawn method I've tried is explained in this blog article here: https://rpgmaps.profantasy.com/orde-on-the-rock-map-analysis/. It's a bit easier than Merelan City, but it will take a bit of time and care to set up. If I were trying to convert this map (image below) into a hollow mountain I would sink the entire city into a dungeon-style depression into the top of the plateau to give the illusion of a cave with the top of the mountain sliced off.

The FCW file for this map is contained in that blog article if you want to use it as a base for your own map.

These are not the only ways of generating the impression of height differences in a map. There are plenty more, like Shessar's tutorial here: https://forum.profantasy.com/discussion/9155/dd3-battlemap-tutorial-part-3-adding-contours

A ditch at city scale is relatively easy because you only need to worry about the general appearance of the thing rather than adding too much detail.

Would something like this do?

That's a fractal polygon of the darkest grass shade drawn on top of the field with those three effects employed to give the illusion that it is sunken into the field. That's a dark glow set to outer, a pale shadow of the same extent, and an edge fade inner that is twice the width of the other two. You could use the same effect in any city map. I will find a way to leave it in the example map for you.

I've made it drain into the marsh and put mud in it instead of grass, so it makes sense in the map now

It sounds like you may have a line width set that is other than zero. Set the line width to zero and try again.

Don't worry - I forget sometimes and still end up drawing a line around an area instead of a filled polygon.

It looks pretty good for a first map. If you switch on the sheet effects those walls should cast shadows and feel a lot more like walls.

Hi Jerolimoloch :)

It sounds like you have something happening there that might be better sorted out by Tech Support. You can contact them through your account page on the Support tab.