I am intensely jealous of those of you who have the pre-painted Dwarven Forge or Thomarillion dungeon and outdoor scenery. As someone who came late to the miniature battles hobby (the last couple of years), I had never felt any need nor desire to buy dungeon scenery: in the 70's and 80's, all of our D&D games were either miniature-less, or we used miniatures simply as placeholders, to show our position in marching order.
It was rare that we actually worried about tactical placement in combat. It was standard operating procedure to inform the DM that we were positioning ourselves in combat in a way to ensure the casters were protected from melee.
After playing my first miniature battle game, I began to appreciate the appeal of this form of gaming, and how it ultimately begat the role-playing form. RPG's will always be my favorite form of gaming, but miniatures battles have their own appeal. While similar to chit and hex boardgames (Squad Leader being among the closest in form) miniature battles give you complete freedom of movement, in 360 degrees. And directing whole hosts of combatants, rather than your character alone, creates tactical options that you might never otherwise consider.
Having come to enjoy miniature battles, I naturally began thinking about creating my own "sandbox", not with actual sand, of course, but a table upon which to play miniature battles. While the sandbox project remains unfinished, I did come across the Hirst Arts website, which has molds from which you can create your own plaster-cast dungeon and outdoor scenery.
I purchased several of the molds. Now, one of my ongoing projects is trying to create my own dungeon tiles, from which I can build dungeons. I have been building several 10'x10' sections, that can be put together in a myriad number of ways (the picture above is nine 10'x10' sections that make a 30x30 room, with two doors). As you can see, I have not yet painted the tiles.
I invested a not-inconsequential sum of cash in the Hirst Arts molds. They were well worth it, but sometimes I wish I had made it easier on myself by going the pre-painted route!