Yao Guai Cave (Fallout 3)

The yao guai cave is a small cave that can be reached by going through the Cliffside Cavern's raiders outpost. At the end of the cave you can find Nuka-grenade schematics.

Alternative way
There is an alternative way to reach the schematics instead of fighting your way through from the beginning: simply jump down to the cavern floor below once you reach the main room, where one yao guai is patrolling. Kill it and proceed to take the schematics, which are next to a few skeletons. Now, go back to where you jumped down. On the side of the cavern, you should see rocks that you can jump and walk on. Navigate your way up and you will find yourself back at the exit/entrance. This way, you can skip fighting the other five yao guai, unless you attract them somehow. Make sure you don't let your follower take the long way around to catch up to you. Best to just tell them to wait at the entrance to the cave, as they will engage the yao guai and ruin your escape.

Appearances
The yao guai cave appears in Fallout 3

Bugs

 * One of the yao guai may spawn in the middle of the room's main rock pillar when the map loads. It will show up on radar and even becomes alerted to the player (changing "hidden" status to "caution"), but it cannot escape.

Yao-Guai-Höhlen Yao Guai Cave