Well, I honestly have no idea what this quest is. Might be we're thinking of different towers. I mean the one in Protector's Enclave when one can change their appearance for... Zen, I think. Marked by the two-coloured mask on the minimap. As such, I doubt it would be made unaccessible, because... well, money.
Well, I might have gone a bit overboard calling it a library. But, close enough, the upper level of the Tower of Alteration has a splendid room with bookshelves and a few chairs by a fireplace, looks like just the place for a few mages to exchange notes.
There are indeed plenty of places. A few minor taverns around the place, the Tower with its magical library. However, the Moonstone Mask, as far as I know, is the only major area which is not instanced. Unless you have an agreement to meet somebody, it makes finding other roleplayers less likely. They are indeed all…
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