Arbor Chamber
Arbor Chamber is a room in the Tallon Overworld region of Metroid Prime.
Items
Missile Expansion
Without Plasma Beam
It is possible to enter Arbor Chamber without Plasma Beam by going out of bounds in Root Cave.
If you fail you land on the standable collision when going out of bounds, you can either use Bombs or wiggle while not holding L to reach the spot.
Secret World
It is also possible to get out of bounds in this room using floaty jump.