Open the Chasm Ad-Hoc Main Tunnel gate in Genshin Impact: Northwest of the Ad-Hoc Main Tunnel in The Chasm’s Underground Mines is a closed gate. Unlocking it will enable you to explore the northern cave and complete a Hidden Exploration Objective involving the Orb of the Blue Depths.
open the Chasm Ad-Hoc Main Tunnel gate in Genshin Impact
How to Unlock the Ad-Hoc Main Tunnel Gate
The gate’s key is north of The Serpent’s Cave. Follow the way up from the Teleport Waypoint to the marked spot.
Investigate the glowing place to get the Miner’s Key. You’ll pass four additional Investigate sites on the way to the region, so check your Inventory to ensure you got the key.
Continuing north may lead you to a blocked route with Exploding Barrels. Archers may attack Exploding Barrels to demolish the boulder and open the passage to the Ad-Hoc Main Tunnel. On the other side of the boulder, repeat.
The Ad-Hoc Main Tunnel’s Locked Gate
Find the locked gate marked in the picture above to use the Miner’s Key. Skeld, a Shadowy Husk, and a Precious Chest await inside. Another keyless entrance is at the room’s edge. It takes you to the northern cave, where you may talk to a Seelie and claim Lumenspar and Chests.