There is a hidden Lumenspar locked behind a gate in the Chasm's Underground Mine. Check out how to get that Genshin Impact Lumenspar here.

I. Hidden Lumenspar Location

The hidden Lumenspar is locked inside a secret room in the North of the Ad-Hoc Main Tunnel. It's very close to the northern Teleport Waypoint here. From the waypoint, you head west and glide down to the bottom ground. Then, you will see the gate and the Lumenspar locked inside.

Enter The Secret Room
Open the gate to get the hidden item.

II. How To Get Hidden Lumenspar

This locked room requires a key to open. But you have to find two map fragments first to find the location of the treasure chest that contains the key to open the gate. Here are two places to find map fragments:

  • Northeast of the Ad-Hoc Main Tunnel: the first map fragment is hidden inside a satchel hanging on the column of a small hut near the mine stone wall.
  • Near Lumberpick Valley in Liyue: the second map fragment is hidden inside a bag in the tent of Treasure Hoarders. You can get it while doing the Yanbo the Millelith’s Undetected Infiltration world quest.
Treasure Map
Two locations of map fragments.

After getting two mag fragments, you have a Treasure Map of Treasure Hoarders. Follow the instruction on the treasure map to find a Treasure Hoarders' tent in Glaze Peak marked on the map. There are some bombs next to the tent.

Next, you can activate the bomb or use Pyro elemental skills to burn the hay on the ground to reveal a trap door. Get close to it and press the button to access the Den of Thieves. After getting the key, go to the gate and open it to obtain the hidden Lumenspar.

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