In Tirisfal Glades the Undead have taken control of many of the towns such as Deathknell and Brill. There is also a city, Undercity which is under a old Human castle. The Undead also control the Bulwark on the eastern border where Undead launch their attacks to take Western Plaguelands. The Undead are not the only ones in Tirisfal Glades though because the Scourge still have control over a few farms and there is the Scarlet Crusuade who control a few outposts in the region.
Tirisfal Glades used to be part of a Human Kingdom in north Lordaeron ruled by King Terenas but Arthas his son killed him then killed all of its people and turned them into his Undead minions called the Scourge. However after the Third War Arthas lost some of his power which allowed some Undead to free themselves and take Tirisfal Glades as there home.
Between Brill and Undercity there is two zeppelin Platforms which goes to many Horde bases such as: