Liminal space

Liminality (English Liminality, from Lat. līmen — threshold, threshold value) is a physiological, neurological or metaphysical term denoting a "threshold" or transitional state between two stages.

In this case, we are talking about the concept of spaces of a certain type that make you feel uncomfortable, uncomfortable, sometimes fear or even horror. Liminal spaces are entrances, corridors, metro stations, sprawling corridors, eerily lit rooms and alarmingly open spaces, stairwells, elevators and other similar places. Usually there are no people or living beings in them, although there may be barely noticeable signs of their presence. Usually being in it, or even just watching in a photo, a person has a feeling of ambiguity or disorientation, uncontrollable fear, discomfort and deja vu. 

In 2022, two psychologists from Cardiff University in Wales studied the phenomenon of liminal spaces and found that the anxiety we experience is, in fact, the effect of the "sinister valley". Ie, the feeling of eeriness arose as a result of deviations from familiar patterns: spaces are very close and familiar (hotel corridor, empty airport, dark basement), but there is also something unfamiliar - the lighting is off or weak, there are no people in a public place, the proportions seem unreal.

There are several stories in folklore about those who could only be killed in the liminal space (for example, in Welsh mythology, this is Lleu).

A whole movement of people who enjoy and even collect photos of such places has appeared on the Internet.