Hello.
I've been playing around with a few ideas and wanted to show you what I'd come up with and get some feedback and ideas.
I'd been wanting an interior board for some time, but I was torn between a starship interior, underground vault complex, an evil lab layer or a more traditional dungeon/labyrinth.
I basically wanted something I could use for both Sci-fi and fantasy dungeon crawls.
I thought about it and in the end settled for the following base board as it seemed to me to be suitable for most of the above as well as a city board.

Before I actually made the board I played around with the idea making the walls out of expanded foam. Because the foam is very light I wanted some way of attaching it to the board temporarily, so I thought of sinking magnets into the surface of the board in a grid and sticking sections of cut-out beer cans on to the bottom of the walls, but it seemed labour intensive and cost prohibitive.
I thought about doing it the other way round, putting the magnets on the walls and the beer cans on the board but I didn't like the finish I got on the board.
In the end I went for the scribing method that Jack (the Lazy Forger) had posted in a tute. I'd already used it on smaller pieces and liked the effect. The results you get for the amount of time and effort needed are great.
I stuck with expanded foam for the wall sections, a) because I already had a sheet of it left over from making hills, and B) because I'd seen a tute by Theomar the Pious where he showed how to work it with a pencil to sculpt stone walls. I gave it a go and liked the result.
I overcame the weight issue, (the foam has very little weight so I thought it'd move around the board at the slightest sneeze,) by sinking three washers into the base of each wall section. So far this seems to be sufficient to stop the walls moving around too much during play.
This is what I've got so far.

I reckon I need three times as many wall sections, and then I want to do some wall sections with doorways, some pillars, some arch sections, stairs, a well and something to reresent a trap door, and a stairwell down to the next level.
As of yet I'm stumped on the stairwell down, I can't think of of a good 3d way to represent it, might have to go for a 2d representation.
Regards the doors, I've seen some by Pardulon and Fenris that looked pretty good, but my idea is to have them the same size as some Antenocitie's sci-doors I already have, so that by swapping the doors and other props, I can have a sci-fi underground complex or a fantasy dungeon. As a result I think I'm going to scratch a few timber type doors up and them cast them myself.
I figure if they're thin enough I'll be able to stick two together back to back to get a double sided door.
Any more ideas or if if I've missed something please let me know.

Thanks