Quote Originally Posted by Mark Oliva View Post
???
The ring around the interior is the overhang of the wood shingle roof. See the outdoor view above. The building has no windows or arrow slits.
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I marked it up to show what I see when I look at it.

If that outer pattern is the roof overhang, then this tower REALLY needs an outer wall.
The symbol used for the inner wall looks great. (I have some personal issues with walls needing to be darker than floors, but that is just personal taste and too many architectural drafting courses).