The backrooms

If you're not careful and accidentally teleport out of reality in the wrong areas, youll end up in the backrooms. Here, it is nothing but the stink of old, moist carpet, the madness of mono-yellow, the endless backround noise of fluorescent lights at maximum hum-buzz, and about 800 million square miles of randomly connected empty rooms where you are trapped. God save you if you hear something wandering around, because by that point, it already knows you are there.

A maze. Mostly known for "level 0" which is displayed as a maze of mono yellow walls, moist wet carpet and fluorescent yellow lights. It became famous from a YouTube series, "Kane pixels". It has 9223372036854775807 levels, that level being the supposed last one. It's displayed as a large, cold spiral staircase.
There are also creatures, called entities in the backrooms. The scariest one by far is "the smiler". But for me, mutated bacteria is the scariest.

The way you enter the backrooms is by "no-clipping" through the walls/floor. As long as you can walk through a solid thing you can enter the backrooms.

The Backrooms is a realm that first appeared on 4Chan. This realm is out of the boundaries of the real world and can only be accessed by nocliping through a floor or wall in a place that inspires deja vu or an uncomfortable feeling of nostalgia. It consists of a never-ending maze of yellow-ish empty rooms with beige carpets, old wallpaper, the smell of mildew and moldy carpets, and the faint buzz of fluorescent lighting.

A really big yellow liminal office building that you get to by no-clipping IRL.

If you're not careful and you "noclip" out of reality in the wrong areas, you'll end up in the Backrooms, where it's nothing but the stink of old moist carpet, the madness of mono-yellow, the endless background noise of fluorescent lights at maximum hum-buzz, and approximately six hundred million square miles of randomly segmented empty rooms to be trapped in
God save you if you hear something wandering around nearby because it sure as hell has heard you.

The Backrooms are an alternate dimension, but one that is not like many other alternate dimensions in the universe. While others seem to be pocket dimensions that are linked to our own reality, the Backrooms runs deep INSIDE our own reality, meaning there is no physical way to enter it. Rather, a person enters the Backrooms when in a state of deep despair, or during sleep.

The Backrooms are a concept first showcased in a post on 4chan, where one user described a realm made up of nothing but infinite, empty, interconnected rooms with horrible yellow wallpaper and loud fluorescent lights. The concept has now been expanded upon and revamped numerous times over.

The Backrooms, in general, are a series of liminal spaces designed to evoke a feeling of eeriness and nostalgia. They are designed to be a form of psychological horror, with the emptiness and eerie feelings as the main point of the Backrooms. They take elements from everyday life, things that one would not ordinarily pay attention to, and takes them out of context to create something uncanny. Something empty. They are designed to feel surreal, dream-like. Often, the structure and physical design of these liminal spaces are completely nonsensical, as if they were not deliberately made, which, of course, only adds to the psychological horror of the Backrooms.

If you'd like a more in-depth explanation, take a look at Solar Sands' video on YouTube on the subject, titled, "Liminal Spaces".

There's also a Fandom site for the Backrooms, at backrooms.fandom.com.

The backrooms are an endless set of office cubicle styled rooms set in a plane slightly agitated from normal reality.

The action of reaching the backrooms is described as "no-clipping" out of reality but there is no natural way to do this.
People who end up in the backrooms are subject to what can only be considered a glitch in reality and cannot be called at fault.
Ending up in the backrooms happens by completely random chance and can happen to anyone.

The backrooms are considered a place that you end up when reality has corrected and irregularity while someone was inside the zone of this irregularity but the zone does not contain area in a normal space and can be compared to how fifth dimensional objects are perceived from the fourth dimension.
Though the backrooms cannot be escaped by any normal means any living being can perform, there are several different fates that can occur while wandering the backrooms.