Oran is a real town in Algeria on the Northwest corner of Africa and therefore bordering the Mediterranean. Here’s a map.
There’s quite a bit to cover here, so settle down now. First, there’s the racial stuff. Rambert’s inquiry about Arab living conditions only makes sense if you know the skinny on the area’s history: France colonized Algeria and it was still French territory in the 1940s; native Arabs were considered "beneath" the French colonists, so racism and the staggering lack of equality – socially and legally – were a big deal.
That’s it for geography. The 1940s were World War II time, at least from 1939 to 1945. We don’t know exactly what year The Plague takes place, since all the narrator tells us in his introductory chapter is that it was "194–." Ah, yes, 194–, we remember it fondly. That was the year of –– and ––. Good stuff. Anyway, since the narrative doesn’t mention everyone being in the midst of a huge war, we figure it’s either after the war, or there is no war in this fictional world, or – and this is highly likely – no one in Oran cares anyway. But the setting of 194– still matters, especially when you keep in mind that many see The Plague as a war allegory. The inaction of the Prefect and other authorities becomes about not standing up to injustice, and Rieux and Tarrou are seen as heroes of something like the French Resistance. (Check out "Symbols, Imagery, and Allegory" for a slew of examples of war stuff in The Plague.)
But let’s talk about the narrator’s description of the actual physical set-up of Oran. It’s ugly, he says, a "thoroughly negative place." (If you want to go the allegory route, in which Oran = everyone’s hometown, then it looks as though Camus’s view of the world is indeed rather bleak.) The narrator mentions that "the seasons are discriminated only in the sky," which suggests that things are just as mundane and repetitive before the plague begins as after it has settled in. We further learn that "Oran is grafted on to a unique landscape, in the center of a bare plateau, ringed with luminous hills and above a perfectly shaped bay." Interestingly, Oran is already gated in from the rest of the world, reminding us that words like "isolation," "confinement," and even "exile" are relative and could be applied to the town just as easily before the plague as after it. Lastly is his note that Oran "turns its back on the bay, with the result that it’s impossible to see the sea, you always have to go look for it."
Trust us; all this information isn’t accidental. Even this last line about the sea is pregnant with implications about the state of existence in Oran. The very notion of seeking out, of looking for something, is a big tenet of existentialism. That the citizens can’t live without choice, that they must go looking for what they wish to see, is the way an existentialist would describe any man.
Yet another lesson in why we should never, ever ignore the setting of a novel. Unless it insults you, in which case, give it the silent treatment for a bit.