Lord Jim is technically a British novel, though almost none of the novel's action takes place in Jolly Old England. This novel really belongs more to the British empire, specifically Southeast Asia and the Pacific Ocean. As a former sailor, Conrad kept the action in places familiar to him – on boats at sea, at seaports, and on islands. This is a novel written by a sailor about sailors, so it makes sense that the bulk of the action takes place at in the more watery corners of the world.
Unfortunately, Conrad doesn't seem all that interested in painting a vivid picture of these environs. He's much more interested in Jim's story. Perhaps that's why he doesn't go into much detail when it comes to the locations where events go down.
The bulk of the novel takes place on board the Patna, at the anonymous port where Jim's trial takes place, at Stein's house, and on Patusan. These places are all tropical and filled with eclectic individuals, but ultimately they are fairly forgettable. They're merely backdrops for the more exciting human dramas going on. And even when Conrad does give us details about the setting, it's often the human element that draws his attention.
At a description of Jim's trial, the characters seem to become part of the setting itself. Conrad tends to define places by the people in them.
[T]he big framework of punkahs moved gently to and fro high above his head, and from below many eyes were looking at him out of dark faces, out of white faces, out of red faces, out of faces attentive, spellbound, as if all these people sitting in orderly rows upon narrow benches had been enslaved by the fascination of his voice. [...] The light of a broad window under the ceiling fell from above on the heads and shoulders of the three men, and they were fiercely distinct in the half-light of the big court-room where the audience seemed composed of staring shadows. (4.1)
These nameless faces provide the backdrop against which the trial occurs. Though these faces are, of course, people, who they are and what they are saying isn't of huge importance. Conrad is more interested in the image because it helps him set the scene
The setting for Jim's trial is relatively generic – it could be taking place at any number of locations in the South Pacific. What's important isn't so much the location as the mood, the people involved, and the overall atmosphere defined by people. The same is true for the other settings of the novel, which are filled with tropical "stock footage."
The setting details we do get are often very atmospheric and mirror the characters' moods and emotions. Take, for example, this description of Stein's house:
We passed through empty dark rooms, escorted by gleams from the lights Stein carried. They glided along the waxed floors, sweeping here and there over the polished surface of a table, leaped upon a fragmentary curve of a piece of furniture, or flashed perpendicularly in and out of distant mirrors, while the forms of two men and the flicker of two flames could be seen for a moment stealing silently across the depths of a crystalline void. (20.37)
Dreamy, right? Swirls of light and darkness, empty rooms, a crystalline void. That doesn't sound like any house Shmoop has been to. But it does set an otherworldly tone for Marlow's encounter with Stein. And it reemphasizes the fact that this entire story is made up of memories, which are always a bit dreamlike and unstable.
That instability comes into play in Conrad's descriptions of the Patna as well:
And all is still. No thunder, no wind, no sound; not a flicker of lighting. Then in the tenebrous immensity a livid arch appears; a swell or two like undulations of the very darkness run past, and, suddenly, wind and rain strike together with a peculiar impetuosity as if they had burst through something solid. Such a cloud had come up while they weren't looking. (9.3)
Conrad's descriptions highlight what is happening more than where it's happening here, which just goes to show that settings matter in the novel only so much as they affect and reflect the characters.
... On the British Empire.
Before you go thinking, okay, so the setting is no big deal, it's important to stop for a second and think about the larger setting in which the novel takes place. It's a little thing we like to call the British Empire, and it's not so little at all. Conrad wrote his novels when British (and European) imperialism was at its height, and European influence was felt in just about every corner of the world.
With that imperialism comes a whole boatload of issues, all of which our characters are grappling with. First and foremost, race relations between white imperialists and their local subjects were tense at the best of times, and violent at the worst. We see this tension hinted at all over Lord Jim, but the novel rarely puts race at center stage.
The Empire, though, is always in the spotlight, with its remote outposts (like Patusan) and innumerable ships (like the Patna). So while we may become totally engrossed with Jim's story, it's important to remember the larger story of the British Empire. After all, Jim's story would never have happened without it.