Caer Darrow

From wow.incgamers.com

An island south of Quel'thalas and east of Lordaeron, located in the centre of the Darrowmere Lake.

Caer Darrow used to be the location of the magical Runestone, erected by Elven druids and inscribed with powerful wards of protection. The Runestone was removed by the Horde during the Second War, and the island was made into a small city. With the start of the Third War, the lord of the castle, Alexi Barov, had become a cultist in the Cult of the Damned, and turned the keep into a school of necromancy, also known as Scholomance.