If I'm ever in mid Wales (which usually is at least twice a year ) I always try to stop by a little shop in Porthmadog called Porthmadog Models (6 Bank Place. Just off the high street ). It's a great shop the owners are always friendly and helpful. It has a bleeding impressive display cabinet (8' x 5') which currently holds a massive (at least 300 hundred off miniatures) Napoleonic battle. Last Christmas It was an American civil war battle. It stocks hundreds of model kits, models and soldiers in various forms. Not many for game systems I play but there are plenty of random bits of scenery all over the shop so I always get something. He also stocks plenty of Amera Plastics. Which are nice cheap plastic terrain.
These are the building ruins I bought this weekend. All they need is to be cut out and based and nice and cheap (£6) building ruins.
I also bought a couple of dead trees for £2 each.
Last time round I bought some pre painted fences which are brilliant little scatter terrain. That's the beauty of this shop they might focus more on models but they have an abundance of terrain for most scales of wargaming. If you're ever that way pop in for a look and a chat cracking shop !