Altus Tunnel is a location in the Altus Plateau in Elden Ring and the home of a dual Crystalian boss. This tunnel also hides a few crafting items and weapon upgrade materials. As part of our Elden Ring guide, we're going to explain how to complete Altus Tunnel.
Elden Ring: How to Complete Altus Tunnel
On this page, we're going to reveal how to complete Altus Tunnel. We'll include the location, a walkthrough, and any additional information, like item drops.
Altus Tunnel Location: How to Find It
The Altus Tunnel can be found directly south of the Minor Erdtree in the Altus Plateau. The entrance is just southeast of the Forest-Spanning Greatbridge, but it’s at a lower elevation that you won’t be able to immediately drop down to. From the Greatbridge, jump down the bridge remains to the north and circle around to the east before heading straight south to find the tunnel’s opening.
Altus Tunnel: Walkthrough
Start by descending the opening lift without paying any attention to the ledges on the way down – they don’t contain anything notable. Grab the Site of Grace and head out to the first fork in the path. Opt to enter the smaller wooden doorway and defeat the miner mage and flying Marionette enemies. This room contains a Smithing Stone  behind some wooden rubble in the corner as well as a treasure chest with a Rune Arc.
Head back outside this room and through the larger doorway to come to another two wooden doorways. Take out the miner mage here before entering the next small doorway to the south. Cull out the three crystal snails in this room that defend some Crystal Darts and Cracked Crystals along the walls. With both of the side rooms plundered, continue forward into the larger mining area.
This mining site is overseen by three flying Marionette enemies which should all be taken out first before taking on any of the miners on the ground floor. After they’ve been taken care of, you’ll be free to gather up the Cracked Crystals and Smithing Stones  strewn about the walls. Ascend the wooden stairs next where you’ll encounter another flying Marionette and a miner mage along with a Somber Smithing Stone  along the right-hand wall and an Arteria Leaf at the end of this upper path.
Go back down the stairs and head for an opening to the south which leads out to a large chasm with a small wooden platform on the right with a Crystal Snail sitting in front of a Golden Rune . With that taken care of, continue deeper into these tunnels by backtracking out to the open mining area and heading eastward to encounter a passage with glowing walls, nine total Crystal Snails, another Smithing Stone  on the right, and a closed wooden door at its end. Cut down the Crystal Snails if you desire before opening the final wooden door and facing two Crystalian bosses.
Altus Tunnel: Boss Fight Strategy
Altus Tunnel: Item Drops and Loot
- Smithing Stone 
- Rune Arc
- Crystal Darts
- Cracked Crystals
- Somber Smithing Stone 
- Golden Rune