From WoWWiki

Northpass Tower is a ruined tower located in the Eastern Plaguelands, and an objective in the Game of Towers world PvP event. It is, as the name implies, the farthest north of the towers, lying along the road to the Ghostlands and Quel'thalas. When players capture this tower, members of their faction can use an alter located inside the tower, which grants a 30 minute buff that increases the player's hp by 5%.

Northpass is another tower likely to be fought over regularly, as the reward and location are both relevant to groups running Stratholme. The possible presence of spectral reinforcements from Eastwall Tower also make this one of the funner towers to fight over.

 [60] Establishing New Outposts

Subzones of Eastern Plaguelands

Blackwood Lake • Browman Mill • Corin's Crossing • Crown Guard Tower • Darrowshire • Eastwall Gate • Eastwall Tower • The Fungal Vale • Hall of Arms • The Infectis Scar • Lake Mereldar • Library Wing • Light's Hope Chapel • Main Hall • The Marris Stead • Mazra'Alor • Northdale • Northpass Tower • The Noxious Glade • The Pestilent Scar • Plaguewood • Quel'Lithien Lodge • Scarlet Base Camp • The Scarlet Basilica • Stratholme • Terrordale • Terrorweb Tunnel • Thondroril River • Tyr's Hand • Tyr's Hand Abbey • The Undercroft • Zul'Mashar