To unlock access to the "Undermine" location (a new game zone from WoW TWW 11.1.0), you first need to travel to Darnogal. There, at the coordinates: /way 42.21, 27.10, you must meet Renzik "The Shiv", speak with him, and accept the quest "When Opportunity Explodes".

Important:

If this quest is unavailable, you will need to complete earlier quests in the World of Warcraft: The War Within storyline. Only after finishing these preliminary quests will you be able to start the quest chain that leads your character to "Undermine".

Where is the entrance and how to get there?

Head to the location The Ringing Deeps. At coordinates: /way 67.02, 78.42 you will find the entrance to the rocky mountain gorge. Enter inside and move straight ahead. Then, at coordinates: /way 77.11, 73.20, you will meet Stelliya. Talk to her, and she will send you to "Undermine".

Note:

Stelliya will teleport you to "Undermine" only if you have completed all the required quests from the WoW TWW campaign for patch 11.1.