That is just one square which you can place in the menu... I'm talking about this:
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Trying to do this in the Menu is impossible... and you can NOT add these after you build it with the 1 tile all around... can NOT be done.
This is on a Normal Castle:
View attachment 124751
When I created my Keep I intended to recreate this here:
View attachment 124752
But found that it is IMPOSSIBLE... as the game believes that corner to not be in your house. So it would be EMPTY and the rest would be there but you can't put anything on that corner.
So you can NOT put the crenellations in afterward.. with the tiles you can build ... as it can't be done. Which is annoying as hell... You can put them anywhere but the NW corners...
Was able to reproduce the Crenellations here:
View attachment 124753
But doing the rooftop found that it wasn't possible to put them in the NW area... which was irriating...