Stratospheric citadel tile shows up, but when I embark, I can't find the citadel

[Hedgerow]

When I embark into a stratospheric citadel square, it's like it's just a really big rocky crag tile. I fight my way through and get to the windmill and destroy it, but at no point do I see a citadel. Do I have to look in the sky or something?

Thanks for any insight!

[x4000]

Once the windstorm generator is destroyed, then send in an NPC to destroy it on the world map.  Cheers!

[Hedgerow]

It says that when I send an NPC it will arrive, but it doesn't say it will do anything else.
Actually, one of the citadels says the NPC will smash it, the other one just says "arrive"

[x4000]

The text is:

Part of Demonaica's method of retaining power over this land; you won't be able to destroy him without taking down both citadels.  First you'll have to go in on foot and smash the control panel, then you'll need to dispatch other survivors to infiltrate it and bring it down.

Until the citadel is destroyed, Demonaica will protect it with various dangerous spells (snowstorm, firestorm, etc).

[Hedgerow]

Note that it says "control panel" not "wind generator" that in and of itself is a bug.
I put my unit there, though, and now it says he's gonna smash it, so the issues are just textual.
Still worth developer attention, though.
Thanks for the help, x4000!