I just noticed that there are several open space tiles on what otherwise appears to be flat ground (outside) on my fortress embark. Annoyingly, tho definitely funnily too, several of those tiles are directly above rooms in my fortress on the level below.
Beyond looking around the entire ground level, is there any way to easily see which tiles are open space?
Move a z-level above the flat ground you suspect might have holes. Empty space above empty space is displayed as a dot on a cyan background, standing out against the black and green of regular terrain.
I prefer DanmakuGrazer's answer, but there's another way. You could designate a channel over the entire ground level and see which tiles do not fill in. The downside is that tiles with trees or buildings will also be unfilled. You will definitely want to remove the designation before unpausing.
