Sunken Labyrinth

Sunken Labyrinth
Level:	50 - 150
Size:	Small Fellowship
Cluster:	Ashes of Osgiliath
Region:	Eastern Gondor
Area:	Osgiliath Culverts
Location:	[62.7S, 8.8W]

The Sunken Labyrinth is a 3-man World Instance in the Osgiliath Culverts in Eastern Gondor. ^{[62.7S, 8.8W]}

Deeds

Sunken Labyrinth Deeds

Challenge: Subterranean Slugfest

Light Beneath Osgiliath

Memories of the Second Age

Sunken Labyrinth -- Tier 1

Sunken Labyrinth -- Tier 2

Quests

Mablung in the Osgiliath Culverts provides the quest Lost, But Not Forgotten. Finishing this unlocks Ashes and Stars, Chapter 1 which starts a quest chain leading through all three instances in Osgiliath.

Sunken Labyrinth Quests

Bounty: The Sunken Labyrinth

Challenge: Subterranean Slugfest

Sunken Labyrinth -- Tier 1

Sunken Labyrinth -- Tier 2

Mobs

Bosses

Dagron - Troll abomination
Muzgásh - Half-troll abomination

Walkthrough

Despite the common perception, this instance is soloable, and if one only desires the class trait point from Ashes and Stars, can be run, set at level 50.
There are various mobs around, darklings (slugs), abominations, etc., and they get harder as you go along.
The simplest way to get through the first fully-gated area, especially when solo, is to operate the levers (D in the diagram) through the west gate (A). Invoke your preferred keybindings for "select object" (nearest/next/previous), then "use". The "classic" or "traditional" way to open those gates is to run around and use the levers at points A, B, and C, but this is on a timer and will require multiple people, or some sort of speed buff (e.g. run coffee).
In the next area, there are roaming abomination workers and slugs roaming past the opening, pull and dispose of those. Just inside are rats. After you clean out that area, go around the bend and you'll start encountering the mutant orc abomination archers and warrior.
The first boss is found at E. During the fight, an outlet will periodically randomly open somewhere in the maze of his room, and unless it is shut it will continue to spawn another wave of adds. Fight in the center(ish) and watch which direction the adds come from to know which direction to go to shut the outlet. The boss has terrible body odor, and is gaseous.
After the boss at E, the levers at F must be worked to advance. The combination is currently 3 then 1 from the left hand side.
If you are on Ashes and Stars Chapter 2, there is a notebook at the camp at G which must be discovered to advance the quest.
The final boss is at H. After defeating him, a mysterious ranger will run away. If you didn't find the notebook at G, the Ashes and Stars quest will not advance. If you leave the instance then go back inside and get the notebook, then once you reenter H you will again see the mysterious ranger run away. This time, when you leave the instance, the quest will advance.