The Plagueworks are on the left side of the map
The Plagueworks is an area inside the west side of Icecrown Citadel, connected to the rest of the instance by the Spire surrounding the Frozen Throne in the middle level of the zone.
The Plagueworks is a laboratory for creation of potions, vials and containers of the Plague of Undeath and blight slimes. It is also the factory where several Abominations and horrific scourge creations are made. Professor Putricide is the leader of the Plagueworks.
A central theme of the Plagueworks seems to be the green liquid plague seen in Warcraft III and classic World of Warcraft, alongside the orange [Blight Crystal] plague seen throughout Northrend (mainly in Zul'Drak).
The Plagueworks opened on January 5, 2010, 28 days after the opening of Icecrown Citadel.
The entrance to the Plagueworks
The unopened doorway to Putricide