Slitherine

When playing Judea you can build them. Do they stack with walls or are they like a Dacian Fortress that doesn't? If they don't stack is there an upgrade path like the Dacian Fortress? Any opinions about how to use them would be greatly appreciated.

I guess I'll try this question another way. To the people that have played Judea, do you build this or just build walls?
Thanks.

If it works like all others, Akropolis etc. then the walls are not additive, but the resist and garrisons are.

Thanks for the answer. The Dacian Fortresses have a great upgrade path but I can't find anything about an upgrade path for the Citadel Towers. Therefore, I'm leaning toward it's not worth using up a slot.

update to fortress