Crusader's Outpost (Nightmare Vale)

From WoWWiki

This Crusader's Outpost is a guard tower located in southern Tirisfal Glades near the entrance to the Sewers of Undercity. It is under the control of the Scarlet Crusade who can keep a watchful eye on the flight routes from and to Undercity from here. It is one of the four Crusader's Outpost towers in Tirisfal Glades. This particular tower is commanded by Captain Perrine who guards a chest that contains [Egalin's Grimoire].