The Nexus, a dungeon hub, is an ancient ice fortress found in the center of Coldarra, in Northrend's Borean Tundra.
It is a column of magical energy surrounded by levitating earth-covered rings with ice caves underneath.
The Nexus is an extensive series of caves and tunnels under Coldarra, containing wings leading to two 5 man dungeons and one 25 man raid.
The Oculus is a high level 5 man dungeon located within the Nexus.
It is unique because it allows each player to control flying drakes with specific roles (tanking, healing, damage dealing) to complete the dungeon.