Isle of Mysteries
The premier location for the study of magic. Originally created as a safe (distant) location for experiments by a cabal of Wizards and Sorcerers the inevitable stream of those seeking to study under the masters doing the experiments led to a significant population on the island. Having long since been formalized into multiple colleges of study the 'tower' is a warren of unplanned buildings merged into a single entity. Stories of lower tier students changing their area of study 'because they couldn't find their way back' are common.
Being unreachable by mundane means for half the year was considered a bonus when it was created, this is seen as less useful for a functioning college. An annex was created for the induction of new students and the lowest tiers of education in the town of Stormhaven with mixed feelings. No one really wants young wizards learning to warp reality in their back yard, but both the Crowns in Rhen and the Duke in Bakkarholt like the idea of having a center of magic learning in their territory. Rhen has it's own Tower of Magic already, but no good access to the Isle and the Mage Council on the Isle prefer their independence. The Stormhaven Tower was only recently recognized officially after a couple decades of political wrangling.