@thehawk makes a good point about ancient sewer systems. I think the earliest definite sewer pipes date to around 4000 BCE in what's now southern Iraq, at the ancient cities of Eshnunna and Uruk, although more sophisticated sewer systems survive archaeologically from the Indus Valley civilization around a millennium later (c. 2300-1800 BCE). Most were of brick or clay construction in various forms.

There is a boat at the ferry crossing landing on Ferry Road, but it's a sailboat.

Ferries don't even need to be especially boat-shaped, of course, as something like a square plank raft will do, particularly of the kind that uses pull-ropes to cross the watercourse. Some of those types were still in use in places well into the 20th century (notably the more rural areas, and on relatively narrow crossings). Depends what you need, where and when.

Glad we got that sorted at least! I did know about the hotspot disabling, but wasn't online after you replied yesterday. Thankfully, we always have Monsen 😁!

When you hover over the "Open PDF Mapping Guide" words, do you get a "pointing-finger hand" symbol on your cursor instead of the usual arrow one? I ask, because you mentioned the hotspot does not seem to be active, and that you "assume" this is what you have to do, whereas the change to the pointing finger cursor icon ordinarily confirms it's where you need to click.

I think Adobe took over half a minute to open my mapping guide, but I find the Adobe Reader startup is often pretty slow from "cold" these days. (Too much unwanted and unrequested Windows clutter that keeps getting dumped on my system, I suspect...)

This is based on a download and installation done within the past twenty minutes, incidentally (so around 17:15 UTC on Dec 2).

I suspect you'll need to post the FCW file here to get some definitive answer to why these symbols are showing as green and with a green edge, as there are too many variables to try to guess at something useful without that information.

The wall and tower symbols in Darklands City go on to one or other of the SYMBOLS Sheets. There is a dedicated SYMBOLS 2 (walls) Sheet, and another SYMBOLS 3 (towers) Sheet, although you would need to have selected either of those Sheets to have the walls (or towers) go on to one of them as you place the symbols. Otherwise, if you have no other SYMBOLS Sheet selected, they will default onto the normal SYMBOLS sheet only.