The reason I pointed at the tower I did was that it's one of the two sites linked to the site government that's listed as a neighbor.
As far as I could see, the neighbor list isn't listed by proximity, but rather by entity id (i.e. the order in which they are scanned).
Anyway, using info exported to Legends Viewer, it seems The Glittery Bunches resided in that tower until it was destroyed, and there's a fair population of experiments, plus a group of non necro gobbos who are slowly repopulating the site.
However, taking a look at Taxriddle, pointed out by Shonai_Dweller, shows that The Fiery Society that formed it was formed by The Glittery Bunches, and this happened after the original tower was destroyed. So, yes, a Tower government working out of a non tower they've founded.
All of the locations containing blank neighbors I've seen are in the same vicinity and contains The Glittery Bunches as one of its neighbors.
Thus, it seems the site government The Glittery Bunches is still sort of active through its offshoot site government The Fiery Society, but since it doesn't have a tower, there's no "Tower" text to display for it. It seems there are a few DF issues here:
- Why is the original site government listed, rather than the new one? It's logical that it works that way for civs, but not for site governments, and necros are only site based, not civ based.
- Should DF allow for necros working out of structures other than towers, or is this behavior a kind of bug (we don't know yet if they can attack a player fortress)? If so, the Tower description should probably be replaced by e.g. Necro (Tower), Necro (Fort), etc.
- If the Fort should be a real "Tower", why is it listed only in parts of its range?