Hello everyone, nice to be able to start posting again, thanks to Stuart.
A few suggestions of my own:
River crossings (bridges, ferries etc.)
There was a heading in the old forum called Residential. Something like this (Civilian buildings and structures?) would be handy for important or interesting non-military buildings, housing, follies, monuments, etc.
Emergency services - Fire, Police, Ambulance and Coast Guard, Air/Sea rescue.
I agree about the Transport heading - Railways, Buses & Trams, Road Haulage etc.
Ecclesiastical - Churches and related religious subjects.
Highways is another that springs to mind.
Unfortunately this begins to inflate things a bit, but if you want to post about any of these things at the moment there isn't a suitable section.
Start mulling!