Un-removable forts?

[Slaists]

... Especially considering that those fortifications express as fort battles (as opposed to the "walled city") and you can only build forts in friendly territory.
...

Not true, I definitely was able to build a fort in unoccupied Huron territory while I was at war with them.

[Susanna]

Not true, I definitely was able to build a fort in unoccupied Huron territory while I was at war with them.

Yep, that's true. The ingame tooltip is incorrect about that.
First-level forts can built within enemy territory, although upgrades can't.

Susanna/Calapine