Explanation of a quote from The Great Gatsby

I've decided to catch up on all the books we should have read in high school, but before I get to Animal Farm, Of Mice and Men, and Brave New World, I'm starting with The Great Gatsby by F. Scott Fitzgerald. I tripped over a line in chapter 2 that I'm having trouble deciphering. It doesn't seem critical to the story much, but I'd like help with it regardless.

I followed him over a low whitewashed railroad fence, and we walked back a hundred yards along the road under Doctor Eckleburg's persistent stare. The only building in sight was a small block of yellow brick sitting on the edge of the waste land, a sort of compact Main Street ministering to it, and contiguous to absolutely nothing.

Specifically:

...a sort of compact Main Street ministering to it, and contiguous to absolutely nothing.

I understand what ministering and contiguous mean, but I can't scrape off a meaning from the sentence itself. Can someone explain what the author is trying to say here?

Solution 1:

In the sentence

The only building in sight was a small block of yellow brick sitting on the edge of the waste land, a sort of compact Main Street ministering to it, and contiguous to absolutely nothing.

I think that the author is simply saying that the block (or rectangular structure) of yellow brick is contiguous (next door) to nothing, and that the "compact Main Street" (that is, public road of modest size) leads up to it.

Under this reading, the "it" in "ministering to it" is the "block of yellow brick" (a commercial structure large enough to accommodate an empty and unrented shop, an all-night restaurant, and car repair shop); the street is "ministering" to the yellow building because it exists only to connect the building to the intercity roadway that (Fitzgerald points out earlier in the chapter) parallels a railway line on the edge of a "waste land" (which is, in fact, a tract of land covered with ashes—presumably a dump for incinerated garbage from New York City); and the building is contiguous to nothing because it is the only building on this spur street off the main roadway.

The further notion implied by "Main Street" here (as Tim Lymington notes in his answer) is that the three-business commercial building is effectively the business district of the ash dump community—except that there is no real community: no homes, no municipal buildings, no retail shops to serve a town or village of permanent residents; just a place where laborers at the dump can buy a meal and another place where passing motorists can get their cars repaired.