Travel by boat between towns, but maybe only smaller boats or flat bottomed barges incapable of sea travel.
Plentiful water to drink as IRL you do need water every day.
Water mills, for grinding or crushing certain (CR censored) resources in large quantities. Would take quite a lot of wood and stone with a bit of iron to make.
And on that subject how about Wind Mills which would do the same as Water Mills but on land, say high in the mountains and along the coast? They would both have deviation depending on the water level/wind strength. Ah, just realised, no wind, damn. 
But having rivers would have been more realistic from the start if most of the towns were centred around them as well as lakes, with paths connecting only nearby towns. This would create a region of towns connected by paths, and then different regions connected by rivers. This would probably make path upgrades obsolete though, and for that matter road vehicles in general, unless you could somehow create a road between two distant towns.
How about directionally travel, which I understand boats use (none of my characters have sailed yet) If you have already been to a distant town, and maybe mapped your course by river you could then walk or mark a path back to the original town by walking in that direction, e.g. leave town and mark path in direction NNE. Once, or if, you get close enough you can see the town and alter course, this would probably give rather squiggly roads and probably some lost adventurers!
I'm just ranting now, but travel would be generally quicker over long distances because a boat is needed, and easier because a basic boat is much easier to build than a basic road vehicle.
These ideas are probably of more use in CANTR 2.0 which I keep reading about but know nothing about.
... You just can't see them 
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