The poem doesn't tell us a year or city where it takes place. Really, we get very little about the setting at all in this short poem. What we can say for sure, though, is that the poem describes a burial, and that the woman is being buried in a family tomb. So from the very first line we can imagine the kind of cemetery where there would be a family tomb. Instead of isolated gravestones scattered around haphazardly, we can picture little buildings, marking off each family's tomb.
We soon leave the tomb at the surface to dive down into the depths of the tomb, where we encounter not dead bodies, but just the dust of them. Then, we dive even deeper in moving away from the physical: in the last two lines, we enter the territory of human emotion.
The setting of the tomb really is designed to prepare us for that final, two-line observation. The setting of the tomb announces death, invites us to do physically deeper into the place of death, and then asks us to contemplate what might be at the very center of death. In this way, the setting physically accomplishes what the poem sets out to do with its content. Neat, huh?