I've been wanting to get a ruined tower completed for some time for use with Frostgrave, Advanced Song of Blades and Heroes, Warrior Heroes Legends or any other miniature games. Where I work we have a lot of cardboard cores that come in with some of our raw materials as spacers. Perfect for a tower, or at least the start of one.
I cut is apart and stacked on piece on top of the other. I also found some 1/4" thick pink insulation board and cut a circular base that I then scribed a stone pattern on it. On the outside I cut a few pieces of thin cardboard to simulate a stone pattern. Glue to an old CD, prime with grey paint and I had a good start.
The fun part of a ruined tower on a table is the elevation it can provide for missile armed troops and fire-ball throwing mages. So I added to levels of partially ruined wood floors. The first floor started with a piece of cardboard cut to the inner diameter. I then glued pieces of wooden stir sticks left over from a special event where I work. Then painted with a wash of thinned down brown paint. I then dry brushed with lighter browns to give a weathered look.
Thanks for looking!