Lunarium Key is an Key Item in Bloodborne.
| "Key to the lunarium facing the lake on the second floor of Byrgenwerth College.
In his final years, Master Willem was fond of the lookout, and the rocking chair that he kept there for meditation. In the end, it is said, he left his secret with the lake."
- Unlocks the Lunarium in Byrgenwerth College.
- On a counter, up a ladder near the top of Byrgenwerth College.
- There is a bug in Bloodborne version 1.01 and below that can prevent this key from spawning if the player has used the Small Resonant Bell or Sinister Resonant Bell items in the Forbidden Woods. Update to v1.02 to prevent this bug from occurring.