The Campfire

One of notable details in S.T.A.L.K.E.R.. Sometimes NPCs will gather around campfires.
Note that they won't just sit there - they will be talking, swapping jokes and stories, taking a nibble from a baguette/sausage or even play guitar.
Also note that sometimes it's NPCs from different groups that aren't directly at war with each other. E.G. in this case one of NPCs is a Dutyer.