This article contains plot or progression spoilers. Continue at your own discretion!
The Beneath is a location accessed after unlocking the Golem Maintenance section of the Collapse, it can be accessed through a special gate in the third room of the Clemens Romanus, or through the many other entrances from Jokzi Ozo and Parasite. The area seems to be the bottom of the ocean, in line with the Clemens Romanus being a shipwreck.
Initial Visit
On your initial visit, Moth will ask if you're alright, saying that everything on their end is complete garbage, and asks if the Interloper is still rendering something. Moth talks about how rendering an area like this is, but makes a theory about why the Interloper can render this area at all, Moth then tells the Interloper to explore the area and see what they can find.
Walking across the area, there is an entity hunched over, looking like a Bright Cousin with a camera for a head. Interacting with it (the interaction called "what are you looking at") downloads an image onto your computer titled "EFFIGY", seemingly of the Memory Hole of the same name.
Continuing to the next room, there is another entity, standing up straight with a camera for a head, similar to the previous one. Interacting downloads an image titled "abyss", which seems to be an image depicting the bottom of the ocean, with an eye near the top. If you have the Unity mask equipped, and try to use the Unity ability, it will download an image titled "nothanks", which is the "abyss" image with the Unity ability's rainbow overlaid on top.
To the left of this room, you can find a gate leading to another room, somewhat like a maze. Inside, there isn't many points of interest, though there is an Effigy at the end of the maze, along with a S W AL KK there, complaining about a car problem.
To the right of the Streetlamp Gate, you can go to Parasite.
Streetlamp Gate
Alternatively, you can go to the Streetlamp Gate, it brings you to a city-like area, although it is underwater. Entering a nearby building, you are faced with what seems to be an extremely incoherent version of Kazki.
Going past the building, you can find the final gate, which leads to an alternate version of the pier from City Surface, but underwater. There are two Effigies here, and going past the pier brings you to the City Surface's version of the pier. You can go back and forth from the pier if you wear the Hunger Mask or have low GAD.
Jokzi Ozo Gate
Jokzi Ozo is a sublocation that can be accessed via the gate to the right of the entrance in the first room of the Beneath, as well as the Cache.
Crashed Dull Vessel Gate
Entering the gate to the right in the second room brings you to Our Dull Vessel but in a very warped and disorganized state, seemingly crashed in presumably the bottom of the ocean.
Heading down the climbing wall, you can enter a room with another room at the end, with no way to get there. Though, there are invisible floors that allow you to go through, going through, you will see Akizet's personal room on her Dull Vessel.
Parasite Gate
Parasite is a sublocation that can be accessed via the gate to the right of the Streetlamp Gate in the Beneath, as well as Our Dull Vessel via the Parasite Plane (only if GAD is incoherent or you are wearing the Hunger mask).
Streetlamp Gate
Entering brings you to a version of the pier in Their City, but as usual, underwater. On the pier, there are two Effigies you can interact with. Using the Unity Mask, you can bring them to Jokzi Ozo.
Walking past the pier brings you back to the pier in Their City.
Entities
Streetlamp Gate
Locations
Images
