The colloquial “third place” is, as I understand it, a (usually) public place OUTSIDE of Home or Work where people can meet, hangout, play, or just exist without the expectation of spending money or being productive in some way. Examples would be Parks, Libraries, old-timey Public Houses and Cafes, Playgrounds, Forests and Wilderness within walking distance, and more.

Car culture killed a lot of that by removing the ability to reasonably walk places outside major metro areas, as businesses relocated to cities, and because they straight up increased the fatality rate for walking substantially. Internet Culture also killed it since you can just talk to your buddies through the Demon Rectangle instead of meeting IRL.

In sociology, the third place refers to the social surroundings that are separate from the two usual social environments of home and the workplace. Examples of third places include churches, cafes, bars, clubs, libraries, gyms, bookstores, hackerspaces, stoops, parks, theaters, among others

https://en.m.wikipedia.org/wiki/Third_place