Bloodborne Wiki
Lunarium Key
Lunarium Key

The Lunarium Key is a key item in Bloodborne.


In-Game Description

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.


  • Byrgenwerth:
    • It is found near the top floor of the building, on a counter.


The Lunarium Key unlocks the door to the Lunarium of Byrgenwerth. This allows access to the lookout where Master Willem is sitting on his rocking chair, looking out onto the Moonside Lake.


  • This key is necessary in order to progress through the main questline, by granting access to Rom's boss fight.
    • One can use the Fluorescent Flower to completely bypass the need of this key, and by extension, the need to access the mansion. All that needs to be done is to go from the lamp towards the aforementioned enemy, sprinting and ignoring every enemy, and finally jumping at just the right angle and spot on the small stone fence by using the creature's tail as leverage.


  • A Lunarium is a device that allows one to observe the different motions and stages of the moon. In this case, the Lunarium itself is located on the top of the building of Byrgenwerth, but allows one to also access the Lookout.
  • This key opens to the outside, where Master Willem resides, which begs the question of "why" it is locked in the first place. This is possibly relating to theories pertaining of the "Imposter Iosefka".