I picked up a tub of drywall spackle because the two part epoxy putty I have used in the past as a terrain base is just too expensive for terrain of this scale. I put a few layers down over the foam-core, let that dry then positioned the base of the cathedral so I could trace out the outline. I used the outline to lay out some floor tiles (to test) before glueing them down. Once I started to glue down the tiles I decided to break some up and adjust them to reflect the damage caused by whatever created the craters. There's a lot yet to do but you get the idea.
Tiles down for a test and then broken up a bit and glued down.
Balcony and some other Cities of Death bits added for detail etc.
Roof piece is magnetized for easier access to the inside.
See magnets installed in the columns. The magnets are a few mm down into the columns while the magnets on the underside of the roof piece stick out a few mm. This helps keep the piece in place without any side to side movement.
Several of the tower floors/levels will be magnetized as well. This will allow for easier access as well as give me options for how tall I want it for any given game.
Thanks for looking! Comments and Critiques are always welcome!