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Last Epochis defined by its build complexity and smooth, fluid gameplay. Blasting through monsters with your kit of customized skills never gets old, especially when there’s so much to do in the game. From Monoliths to dungeons, there are several ways to chase your next item upgrade.
The Lightless Arbor is the first dungeon you’ll come across in Last Epoch as you make your way through the main story. This dungeon will have you exploring a dying forest, utilizing Amber’s Illumination to guide you. Below, we’ll take a look at how to find and enter the Lightless Arbor, how its unique dungeon mechanic works, and how to beat the Mountain Beneath.

Finding And Entering The Lightless Arbor
The Lightless Arbor is located in theRuined Era, to theeast of the Council Chambers. To get there, go to theSheltered Woodfrom the Council Chambers, then toThe Surface. Here, you can head north through analternate leveling pathto theShrouded Ridge, then finally to the Lightless Arbor.
How To Get A Lightless Arbor Dungeon Key
To get into the dungeon, you’ll need a correspondingkey. In this case, you’ll first need to find theLightless Arbor Keybefore you’re able to unlock the door and explore the Lightless Arbor.
To get this key, you’ll simply need to get lucky whilekilling and exploringother parts of the game.Monolithsare a good place to start looking for dungeon keys, but there’s a good chance you’ll get a Lightless Arbor Keywhile playing through the main story.

Lightless Arbor Dungeon Walkthrough
Once you have your Lightless Arbor Key, click on the entrance to the dungeon and you’ll be prompted to select the dungeon’sdifficulty. Each difficulty level has higher level enemies but promises better rewards.
Whichever difficulty level you choose, keep in mind thatif you die inside the dungeon, you will be immediately removedand yourkey will not be refunded. This means you only have one shot at clearing the dungeon with a single key.

The Lightless Arbor has a unique dungeon mechanic calledIllumination. While inside the dungeon, a glowingAmber shardwill follow you around. It will start with anillumination level of 100, which willdeplete as you are hit by attacks.
The Amber shard willilluminate the area around itself, while enemiesoutsidethe illumination area willdeal more damageandtake less damage. This means you’ll want to make sure enemies are inside the light as much as possible to remove these buffs.

You will also gain access to theBurning Amber ability, which lets youmove the Amber shard around, allowing you to illuminate areas other than immediately around your character.
As mentioned above, the Amber shard’s illumination level will deplete as you are hit by enemy attacks. To restore stacks of Illumination, you will need tofind and destroy Amber Elementalenemies. Killing one of these enemies willrestore the illumination level back to 100.

With this in mind, explore the dungeon until you reachone of two doors. You can only proceed through one, and each door has differentmodifiers for the rest of the dungeonlike increasing enemy health and damage while increasing the amount of Glyphs the boss drops, and so on.
Repeat this a second time, and you’ll enter the area just before the final boss fight of the dungeon.

The Mountain Beneath Boss Fight Guide
The final boss of the Lightless Arbor is theMountain Beneath. This fight is split intotwo phaseswith different mechanics, the first of which requires you to use theIllumination mechanic.
At the start of the fight, you’ll be in a narrow room with theimmuneMountain Beneath boss at the front. On either side of the arena is aKindlingthat can beignited when you stand next to itwith the Amber shard.
The Mountain Beneath is completelyimmune to damage while both Kindlings are alive, so you’ll need to deal with those first.Move close to the Kindlingor use theBurning Amber abilityto move it next to the Kindling tolight it on fire. After a few seconds, the Kindling will be destroyed and the boss will take a significant chunk of damage.
While you are igniting the Kindling, monsters will appear and the Mountain Beneath will use largeAoE attacks. Avoid these usingtraversal skills, as they can be deadly.
Repeat this asecond time, and the boss will collapse, creating a pathway toEnter the Mountain. Proceed through here to enter the core of the Mountain, where phase two of the fight will begin.
Now, you will have todestroy the Stone Titan’s Heartin the center of the arena. This enemy will use variousAoE attackslike firingexpanding green lasersorconal attacks, so watch for the telegraphs and move to avoid them accordingly. At the same time,additional enemies will appearthat you’ll need to deal with.
Continue dodging AoE attacks while you deal damage to the Stone Titan’s Heart, and eventually, it will go down. Thekey to this fight is playing defensively, getting hits in where you can, butprioritizing dodging the boss’s attacks.