Lightless Arbor Guide for Last Epoch

Last updated on Nov 30, 2023 at 12:00 by Neviriah

The Lightless Arbor is a dark and mysterious forest with living plants, trees, rocks and fierce creatures. Deep in the dungeon, a huge Mountain guards the Vault: a secret room where you can find amazing treasures. This guide will cover everything you need to know about the Lightless Arbor dungeon.



Dungeons are a big part of the endgame in Last Epoch, as you can obtain unique and increased loot from them. One of the available dungeons in the game, is the Lightless Arbor.

In this guide, we will cover everything there is to know about the Lightless Arbor dungeon.


Elements and Resistances

Each dungeon features a unique elemental theme. The Lightless Arbor is all about Poison Damage, so make sure you have enough Poison Resistance to survive.


How to Enter the Dungeon

To enter the Lightless Arbor, you need a Lightless Arbor Key. These keys can drop from random enemies, and can also be farmed from Timeline bosses, as well as within the Arena of Champions. Keep in mind, though, that the Arena has a very low drop rate, so it is not the most recommended way to target-farm dungeon keys.

Once you have a key, you can head to the dungeon and enter. The Lightless Arbor Dungeon is located in the Last Refuge area of the Ruined Era. You can head to The Surface waypoint and follow the path until you reach The Lightless Arbor.

If you are in a party with someone else, you can enter a dungeon even if only one of you holds the dungeon key.


Dungeon Mechanic - Burning Amber

The Lightless Arbor is an old and extremely Dark Forest. Since there are no natural light sources in this dungeon, you will have a floating burning crystal following you as soon as you enter. This crystal is called a Burning Amber. The Burning Amber will only light the path around you, but you can control it with the Dungeon ability Illumination, which will send it out to scout the road ahead of you and can be called back to the player.

Throughout the whole Dungeon, you will have to light Pyres using the Burning Amber. Burning the Pyres will allow you to progress further into the dungeon.

Enemies that are outside the Burning Amber's light will deal more damage while also taking less damage, unless you can lure them back into your light. If they are ranged enemies, they will be especially dangerous foes, as they will try to stay out of your light.

You can attach the Burning Amber to yourself, but you will take damage while having it attached, as well as drain Illumination from the Amber. The more damage you take, the more Illumination will be lost. To counter this, you can put the Amber down when you encounter enemies, and call it back afterwards.

Should you end up losing too much Illumination, you can restore the Amber's full light through killing Amber Elemental enemies that can be found throughout the Dungeon.

Make sure to not run out of light, since you do need it to progress inside the dungeon. This forces you to meet certain gear requirements, such as high Armor and capped Resistances, as well as any defense that will keep you from taking too much damage.



All dungeons will follow a similar layout: two map sections, and an arena with the boss. You have to travel through both maps, and open a door to access the next one. The first door will lead to the second map, while the second door will lead to the boss.

Unlike other games, maps inside the dungeons are not randomized, but some roads will randomly be blocked each run. The doors that separate each map will always have a road leading to them, but it may not always be the same one.



Among many basic opponents, this dungeon also has some challenging enemies that can pose a serious threat.


Special Enemies

There are five tougher enemies that will cause you trouble as they will deal heavy Poison Damage over time, and can pose a serious threat if you don't have enough Poison Resistance. Additionally, those enemies also have some dangerous mechanics that need to be avoided:

  • Amber Elementals: Elementals that deal fire damage and apply Ignite by shooting fireballs in a frontal cone. Their second attack is Upheaval, which is a straight forward shot that deals physical and fire damage. Amber Elementals are not the most challenging, but you will need to kill them in order to recharge your Burning Amber.
  • Hollow Spriggans: Beware of their poison cloud that fills an entire area in poison. The longer you stay inside the cloud, the more poison damage you suffer, so move out of it quickly. Additionally, the Hollow Spriggans also have a ranged attack that deals physical damage, but this one is not much of a threat.
  • Lightless Hive: A huge insect nest that will not move around or follow you, but will constantly spawn Gloom Stingers (insects that will try to sting you and apply poison). You can try to kill it, but be careful and stay out of range if possible, because it will explode on kill and does physical and poison damage if you are in close range.
  • The Rotweaver: These enemies are not very threatening alone, but if you see multiple of them, kill them quickly. They have an ability that will apply poison, and they can attack from range, which can make them very deadly if you get outnumbered and accumulate too many stacks of poison.
  • Rotting Hollow: This one is a very challenging foe with three distinct abilities. Try to be attentive while fighting this enemy, and you should be able to avoid all three attacks without any issue.
    • Biting Swarm is a range ability that will apply poison stacks when hit, so make sure you have decent poison resistance.
    • Shockwave is a physical damage ability where the enemy slams the ground multiple times. Make sure not to be too close when it happens.
    • Frenzied Thorns is another ranged ability that will launch poison projectiles that also inflict stacks of Shred Armor.

The Mountain Beneath and Stone Titan's Heart

The Lightless Arbor boss, known as The Mountain Beneath, is a challenging enemy with two phases and a variety of deadly attacks. You will need to prepare well and learn the patterns of its moves if you want to survive. To this end, here is everything you need to know to defeat the Mountain Beneath.

Before you face the boss, you should know that it has two phases. In the first phase, you will battle against the Mountain Beneath, a massive creature made of stone. In the second phase, you will confront the Stone Titan's Heart, the core of the boss that controls its power. Each phase has its own mechanics.


The Mountain Beneath

Make sure you have enough Burning Amber, as you will need it during the fight. Don't neglect recharging it before engaging the boss.

In this phase, you will fight an invulnerable enemy on a platform. To advance, you will need to use your Burning Amber and ignite the Pyres around the platform, while avoiding the enemy's attacks. When both Pyres are lit, a gateway will open, leading you to the next phase.


  • Pyres: In this phase, you will see two Pyres on either side of the Mountain Beneath. The boss will be invulnerable as long as the Pyres are burning, but it will still attack you. You should start by extinguishing the Pyre on the right side, since the boss's first attacks will be easier to dodge if you stay on the right edge of the platform. When both Pyres are out, you will enter the second phase of the fight.
  • Root Walls: Both Pyres are protected by Roots that need to be burned down. Be careful to not get stuck in the roots as they deal physical damage and will immobilize you for a short period of time.
  • Shockwaves: This is one of the boss's most dangerous attacks. It will slam the ground twice, dealing massive physical damage that can kill you in one hit. You need to dodge this attack at all costs. The boss will always hit the left side of the arena first, then the right side. You will see a warning animation before each slam, giving you time to move away. After the first slam, run as fast as you can to the left side, before the second slam hits the right side.
  • Rockfall: This is another attack that you need to watch out for. The boss will make rocks fall from the sky. You will see circles on the ground where the rocks will land, so you can avoid them easily. Sometimes, the boss will also summon some minions to attack you. You should kill them quickly, before they overwhelm you. The minions are not very strong, but they can be deadly in large numbers.
  • As soon as both Pyres are down and The Mountain Beneath falls over, head to the second phase.

Stone Titan's Heart

This is the final phase of the fight, where you will face the Stone Titan's Heart. The Heart will be exposed at the center of the arena, and you will be able to damage it. However, the boss will still unleash its powerful attacks on you. Be very careful, because if you die, you will lose the chance to get any rewards from the dungeon.

You will not need the Burning Amber anymore at this point of the fight, but you will need a good amount of poison resistance.


  • Titanflesh: Titan's Heart will summon minions called Titanflesh during the fight. They are weak, but they can swarm you if you don't kill them quickly. They deal Physical damage, so watch your health.
  • Spore Beam: The boss will fire a frontal beam requiring you to move behind it as soon as possible. The beam will split into two and rotate around the boss, leaving only a small safe area behind. This attack is very dangerous, as it deals Physical and Poison damage, so avoid it at all costs.
  • Energy Stone: A stone will appear and start spinning around the boss at high speed. It doesn't hurt much, but it can knock you back if you touch it. You can't destroy it, so you have to dodge it until it disappears.
  • Energy Wave: This is one of the most lethal attacks. The boss will send out a wave that covers a quarter of the arena. The wave will deal Physical damage and apply multiple stacks of Poison to you. Be careful, as the wave can overlap with the Spore Beam, leaving you with very little room to escape. You should use a high mobility skill or a cleansing ability to deal with this attack.

Once the Heart is down, the fight is over. This boss can seem very overwhelming if you are a new player, but if you understand the system with the Burning Amber and Pyres and avoid the more dangerous attacks (Spore Beam, Energy Wave, Shockwave), you should be able to go through the fight without too much trouble.




Dungeon Tiers

Dungeons have four levels (4 Tiers) of difficulty that can be selected once unlocked. The first time you enter a dungeon, you will only have access to Tier 1 difficulty. To unlock Tier 2, you will need to clear the dungeon on Tier 1 first. The same applies to Tier 3 and Tier 4. Each tier will make the enemies harder and add modifiers to the dungeon.


Dungeon Modifiers

Dungeons are not only challenging, but also dynamic. Each tier and each floor of a dungeon will have different modifiers that affect the gameplay. Each modifier also gives different rewards for completing the dungeon. Every time you enter a new floor, you will get a new modifier.

Here is a breakdown of all the possible modifiers available for the Lightless Arbor Dungeon:

  • Tier 1, recommended Level 20+
    • Floor 1: No modifiers.
    • Floor 2: Enemies will drop more Glyphs and Runes, rarer Armor, helmets, Jewelry, relics and weapons. Additionally, Enemies will have increased Damage and Health.
    • Floor 3: The Dungeon Boss will drop additional Glyphs and Runes, more rare Weapons, Jewelry, and items. Additionally, Enemies will have increased Damage and Health.
  • Tier 2, recommended Level 65+
    • Floor 1: The Dungeon boss will drop Exalted Jewelry and weapons, additional glyphs, idols and runes, Set item. Additionally, Enemies will have increased Damage and Health.
    • Floor 2: Enemies drop more Exalted Amulets, helmets, relics, rings and weapons, additional glyphs and runes. Additionally, Enemies will have increased Damage and Health.
    • Floor 3: The dungeon boss drops exalted jewelry and weapons, set items, additional glyphs, idols and runes. Additionally, Enemies will have increased Damage and Health.
  • Tier 3, recommended Level 88+
    • Floor 1: Enemies drop Exalted Amulets, helmets, relics, rings and weapons, additional glyphs and runes. The dungeon boss will drop one unique item and many idols. Additionally, Enemies will have increased Damage and Health.
    • Floor 2: Enemies drop exalted amulets, helmets, relics, rings and weapons, additional glyphs and runes. Additionally, Enemies will have increased Damage and Health.
    • Floor 3: The dungeon boss drops exalted jewelry and weapons, additional glyphs, idols and runes, as well as a special unique item. Additionally, Enemies will have increased Damage and Health.
  • Tier 4, recommended Level 100
    • Floor 1: Enemies drop substantially more Exalted Amulets, helmets, relics, rings and weapons, additional glyphs, idols and runes. The dungeon boss will drop one unique weapon and hordes of idols. Additionally, enemies will have increased Damage and Health.
    • Floor 2: Enemies drop substantially more exalted amulets, helmets, relics, rings and weapons, additional glyphs and runes. Additionally, Enemies will have increased Damage and Health.
    • Floor 3: The dungeon boss drops a horde of exalted jewelry and weapons, additional glyphs, idols and runes, one glyph of despair, as well as a special unique weapon and two unique items. Additionally, Enemies will have increased Damage and Health.


Besides the usual loot such as gear, experience, and gold, you can also get some special items that are exclusive to this dungeon.


Boss Uniques

The Stone Titan's Heart has a chance of dropping up to 4 different Unique items, depending on the Tier.

  • Tier 1 +: Peak of the Mountain - Unique Helmet
  • Tier 2 +: Foot of the Mountain - Unique Boots
  • Tier 3 +: Face of the Mountain - Unique Shield
  • Tier 4 +: Core of the Mountain - Unique Body

The Vault of Uncertain Fate

The Lightless Arbor is the only place where you can access the Vault of Uncertain Fate, which will allow you to trade gold for rare and valuable rewards.

Once you defeat the boss, you will be able to access the next area, which will take you to a Vault. The Vault is a special place where you can gamble gold for amazing rewards. When you approach the door, you will see a list of modifiers that you can choose from. Each modifier will have a price in gold, and a corresponding loot bonus. The more modifiers you pick, the more gold you will pay, and the more loot you will get. After you make your choice, you can enter the Vault and discover a treasure trove of gold and chests that you may open and claim.

The Vault modifiers are similar to the dungeon modifiers, but they affect the rewards instead of the gameplay. There are 4 Tiers of modifiers, each offering more options and better rewards. Tier 1 will not give you any exalted items, while tier 4 will have a chance to give you exalted items with a Tier 7 affix.

Here is the maximum amount of modifiers that can be added based on the Tier:

  • Tier 1: 8 modifiers
  • Tier 2: 9 modifiers
  • Tier 3: 10 modifiers
  • Tier 4: 11 modifiers

This dungeon is a great way for players to test their skills and get some amazing loot. The boss might seem tough at first, but once you learn the mechanics, you will be able to beat it easily. Don't forget to equip Poison Resistance and Physical Resistance gear, and bring a lot of gold that you can use in the Vault to make the reward worth the trip.

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