A complex, maze-like space characterized by yellowed wallpaper, damp carpets, and the hum of fluorescent lights. While it appears uniform at first glance, the structure is anomalous, and the same layout never repeats. Rooms with walls and entrances are few; most connect to other spaces, evoking a sense of dread and nostalgia. Alien-like beings with vine-like limbs or dog-like entities are rumored to exist but remain unconfirmed.

A dangerous level consisting of an infinite series of small party rooms where nursery rhymes play. Hordes of Partygoers—humanoid entities with yellow bodies and red smiles painted on them—hunt down humans. There is no known exit, though some have escaped by noclipping out.

A hospital-like hallway stretching for approximately 10km, with red flashing exit signs every 10 meters. Upon entry, a loud alarm sounds, and a massive swarm of dangerous monsters attacks from somewhere behind. The hallway is cluttered with obstacles like chairs and beds that must be dodged while running. There are branches, but they lead to dead ends; to escape, one must keep running straight.

A dangerous space distinct from the Backrooms, reached by a rare chance when noclipping out of bounds. It contains only air and a constant direction of gravity, leading to an eternal fall and inevitable starvation. It is possible to reach this place by falling out of Level 11 or Level 66666 η.

A small, unassuming but charming town where about 4,000 people live. The sound of rust and tearing skin doesn't bother anyone here, and the town welcomes you even if you are exhausted and your clothes are torn from your journey. Navigating the town isn't easy, but by walking together, you can make more acquaintances.

A vast structure of white tiles submerged in water. It is characterized by dry air and shimmering warm water, with the water level varying by location. It features orderly details within a non-Euclidean overall structure. The warm water, containing magnesium sulfate, has pain-relieving effects. Numerous windows let in light, but what lies outside is unknown.

A safe, small hot spring level and a popular spot that provides healing and vitality to many wanderers. While the mineral-rich waters restore the body and mind, soaking for too long is dangerous. However, mysteries are hidden in this peaceful place, and it is said that those who learn the truth never return. Curious wanderers should proceed with caution.

A vast warehouse-like space with concrete walls and floors, featuring exposed rebar in places. Fluorescent lights are installed throughout, and a low-lying fog of unknown origin hangs in the air. The fog condenses to form puddles in irregular spots. The structure follows normal geometry, containing various spaces such as rooms, stairs, elevators, and long corridors. Crates containing supplies randomly appear and disappear; while they hold useful items like food, water, batteries, and medicine, they may also contain hazardous or nonsensical objects. Fluorescent lights flicker or turn off for minutes to hours at a time. During blackouts, hostile shadow-like entities appear and supplies vanish, making a portable light source essential. One can travel to The Hub through specific procedures. Drawings and diagrams on the walls may change when they leave your line of sight.