Leigh found this site Showcase Terrain.
They make and sell their own terrain (as well as miniatures).
It was in another thread that I have deleted, so I have re-posted here. Thanks Leigh - I will have a look (and add a link in the Purchasing Section on the Side Nav Bar if people think they will use it).
“It is amazing what you can accomplish if you do not care who gets the credit.” – Harry S. Truman