This is a bit of a spoiler, but there are very good, plot-related reasons for apparent inconsistencies in the Olonkulet thread where the date of Olonkulet's existence is concerned.
Suffice to say, Olonkulet must happen before Waterbore, but it could happen coterminously with, before or even after any or all other fortresses. All that is known for sure is that it will seal itself off from the world and die. Basically, don't worry about timing there.
Also, I mentioned both Abbeyverse and Nist Akath in the Waterbore thread as well, back in the day. So in Olonkulet's time (assuming we go with its death 80 years before Waterbore) both of those are quite young forts, and by Waterbore they've been established for nearly a century.
As for Lanternwebs... nobody says the current Lanternwebs is the first town ever called Lanternwebs, do they? Hee hee. I'll leave that one to Rysith to figure out.
The Lanternwebs mentioned in Hateslaughter is definitely Ry's Lanternwebs, by the by, and that's after both Waterbore and Olonkulet. Yes, I actually have an internal chronology for all three of my fortresses (and I still have the save for Hateslaughter, I can come back to that eventually, but I'll have to remake Waterbore to complete that story someday).
Probably safe to assume all 2D forts (Boatmurdered, Copperblazes) happened before any of the 3D forts, aye? Stuff of legends and that.