The word you looking for is “liminality”. I always see it used on tumblr to refer to physical places that seem kind of eerie, but the term is inherited from anthropological use, where it refers to being in a transitional “threshold” state between two more established identities or roles. Most traditionally it means being in between formal rites of passage. Not quite here nor there.
A “liminal space”, then, is somewhere that’s not quite a destination in and of itself. Bus stations. Airports. Train cars. Applied more broadly, it’s anywhere that just has that “not a real place” vibe – like deserted grocery stores or the DMV, or somewhere that isn’t currently serving its intended function, like abandoned fairgrounds or water parks in the winter. Eerie vibes.
BUT I really do encourage people to think about liminality in its original application more often – I think it’s a super useful concept for talking about stuff like gender transition and other weird complicated “not fully here nor there” social states.