A big gaping hole in my collection of terrain is bridges. Especially for WW2. The campaigns in Holland seemed to focus on bridges a lot and the numerous waterways made capturing or defending these extremely important. But your standard wooden or arched stone bridge from ancient or horse and musket gaming isn't going to suit the requirement of being an important objective (I'm lacking in those too, but that's another day to spend with some card and glue).
There is a nice Model Railway hobby store in north London (Ontario) called Broughdale Hobby that I try and go to for my terrain needs. Their prices on Woodland Scenics products are usually very good. Last year I was there and picked up an Atlas Models HO scale truss bridge for railroad layouts for $8.00.
I had to make some ramps out of foam. I also replaced the railway tracks with a road bed made from card and scored to look like wooden planks. But a quick grey dry brush and some brown ink for the wood and we have this:
I made the canal side retaining walls from the flexible rubber cobble stone road sections sold for those Christmas Village sets you see in the department stores.
Here's some of my new Canadian vehicles trying it out. Presumably the sappers have already removed the German demolition charges.
It spans the big resin river I made for 25mm Medieval armies quite nicely. I think my small force of Fallschirmjaegers will be defending this quite soon!