Last Epoch: How to get the Lightless Arbor Key

In Last Epoch, dungeon exploration plays a critical role in endgame progression and loot acquisition. Among the most mysterious and rewarding of these dungeons is the Lightless Arbor — a deep, shadow-filled challenge that tests not just your build, but your patience and strategy.

However, before you can venture into its dark depths, you'll need a Lightless Arbor Key, a special item required to access the dungeon's gated entrance. It offers valuable rewards, a unique illumination mechanic, and a thrilling experience not found anywhere else in the game.

That said, the key cannot be acquired easily. It must be earned through specific activities and progression paths in Last Epoch. Knowing how and where to farm the key will not only save you time, but also allow you to run the Arbor multiple times for loot, experience, and gold.

In this guide, we’ll walk you through all the known methods of acquiring the Lightless Arbor Key in Last Epoch and how to maximize your runs inside the dungeon.

How to get the Lightless Arbor Key in Last Epoch

The Lightless Arbor Key in Last Epoch (Image via Eleventh Hour Games)

Situated in the Ruined Era of the world, the Lightless Arbor is a major dungeon within the game. It introduces a unique challenge involving darkness mechanics, where enemies become stronger in unlit areas. Hence, managing a special light source becomes crucial to survival.

Before taking on this dungeon, you’ll need the proper key. Here’s how to get it.

Can drop from the Monolith of Fate

Monolith of Fate (Image via Eleventh Hour Games)

The most reliable way to farm Lightless Arbor Keys is through the Monolith of Fate system. This core endgame feature allows you to fight through various timelines filled with modifiers and elite enemies. You can defeat timeline bosses to increase the chance of dungeon key drops.

High corruption levels improve the drop rate, making farming more efficient the deeper you go. Keep an eye out for echo modifiers and boss drops that specifically mention dungeon keys — they’re your golden tickets.

Arena of Champions

Another potential source for the key is the Arena of Champions, a wave-based challenge mode. While not as consistent as Monoliths, there’s still a chance to earn dungeon keys here.

Keys start appearing after wave 20, with better modifiers unlocked after wave 30. While this method can supplement Monolith farming, it isn't as efficient unless you're pushing high waves.

Vaults of Uncertain Fate

In Last Epoch, the Lightless Arbor Dungeon itself can drop Lightless Arbor Keys. Once you’ve completed a run in Lightless Arbor, you’ll gain access to a special loot room called the Vaults of Uncertain Fate. This room allows you to invest gold in modifying the rewards you receive — and yes, it can give you another Lightless Arbor Key.

Investing in modifiers that duplicate rewards increases your chances of earning extra keys. Smart gold spending here can lead to chain runs, letting you re-enter the Arbor multiple times.

Where to find the Lightless Arbor Dungeon in Last Epoch

Lightless Arbor entrance (Image via Eleventh Hour Games)

Once you have the key, it’s time to locate the dungeon:

Head to the Ruined Era.
Use The Surface waypoint.
Move north into The Shrouded Ridge.
Head north until you find the Lightless Arbor entrance.

Alternatively, you can right-click the key in your inventory to automatically mark the dungeon on your map. This is super handy if you’re not sure where to go.

Inside the Lightless Arbor: The Illumination mechanic

This dungeon in Last Epoch comes with a unique twist: darkness empowers your enemies, and only your Burning Amber light source makes them vulnerable.

You’re granted a crystal called the Burning Amber, which illuminates your surroundings.
Use the Illumination ability to send the light forward or recall it, giving you full control over its position.
Taking damage causes the light radius to shrink, making it harder to stay safe.
Defeat Amber Elementals throughout the dungeon to restore the Amber’s power.

Keeping enemies within the light is vital — they hit harder and resist more damage when they’re in the shadows.

Tips to farm Keys efficiently

Stick to Monoliths for the best key drop rates.
Use fast-clearing builds to speed up your runs and increase the number of key opportunities.
Don’t forget to stockpile gold — you’ll need it for the Vaults of Uncertain Fate if you want to maximize your chances of getting repeat keys.
Plan around high corruption timelines for better loot and key drop scaling.

Whether you're chasing endgame loot, diving into deeper difficulty layers, or just love exploring the dark unknown, the Lightless Arbor offers a thrilling and unique experience in Last Epoch. Earning the Lightless Arbor Key takes some grinding, but the rewards — and the challenge — are well worth the effort.

Check out our other guides on Diablo 4:

About the author

Jagaran is an MMO and ARPG writer at Sportskeeda. His involvement in the gaming industry also includes working as a concept artist and as a narrative designer.
At age of nine, Halo: Combat Evolved kicked off his love for the medium. He looks back fondly on the times he visited cyber cafes, watching the older boys playing the game and shouting, "Master Chief!"
If given a chance to inhabit a game world, he would eagerly jump into the breathtaking world of Halo.
He admires Ben "CohhCarnage" Cassell for his engaging dialogue and gameplay as well as his critical thinking regardless of how much he loves the game, which encouraged him to spend countless hours in games and technically analyze them.
In his free time, he enjoys writing books, cooking, sketching, and the occasional game of football.

Know More

Edited by Abhishek Manikandan