Just curious as to what some of the biggest mysteries in the game are right now. As well as what the notable missing locations are. I wanna do delving into the lore.
There are plenty of mysteries in ESO to delve into. The other continents like Akavir and Atmora, what's left of Yokuda and the archipelagos of Pyandonea and Thras. There's the Aetherial realms, the infinite realms of Oblivion, the unexplored regions of Black Marsh, the desolate and broken Activity Finder, not to mention parts of Morrowind are unused. The Aedric plane(t)s, the moons that aren't locked behind quest specific instances, and Balfiera which is the island that holds the linch-pin of Draconic reality that is Ada-Mantia.