Azjol-Nerub is a vast underground dungeon hub home to the arachnid-like nerubian who were defeated by the Lich King in the War of the Spider. Located in icy Dragonblight, Azjol-Nerub can be divided into two sections: the Old Kingdom and the Upper Kingdom. In addition, many of the deepest areas in Azjol-Nerub are invaded by Faceless Ones.

Ahn'kahet: The Old Kingdom is the second dungeon located within Azjol-Nerub and was controlled by nerubians until recently. An earthquake pushed Ahn'kahet closer to the surface, exposing the nerubian kingdom to attacks from the Scourge. Now, remnants of the old Nerubian empire, minions of the Lich King, and servants of the Old Gods fight for control in the underground galleries of the Old Kingdom.