Poseidon Reservoir

The Poseidon Reservoir is a location in the Commonwealth in Fallout 4.

Layout
Take caution as you enter this complex. While the layout is small and simple, there are roughly a dozen feral ghouls lying in wait, including a Legendary and a Glowing One. Additionally, the basement is covered in gasoline, flammable gas, explosives, and even a somewhat comical kitchen scale trap that will trigger everything. Upon entering, you'll find a small room with a terminal which can be used to unlock the door downstairs. The kitchen scale trap can be found just inside the door at the base of the stairs then to the right. Also in the basement, behind the locked door is a Master level safe. A key to this safe can be found by venturing to the end of the uppermost walkway and jumping onto the blue platform on the left side. The key is in the corner, near a suitcase. Also on this platform is a Novice locked toolbox.

Appearances
The Poseidon Reservoir only appears in Fallout 4.