My photography teacher has a list of things not to photograph, and cemeteries are near the top. However, this picture is awesome and I think goes above the cliche. Was it your intention to slant the horizon to the right? It still remains balanced if it was.
Well, bless your teacher's heart. I'm sure the list is quite a reasonable guidline to help keep a photographer on track and thinking until a eye has become nature. Cliche subjects should be avoided until a unique interpretation can be made. Not that rules are made to be broken, but there are always exceptions. Here's a couple links regarding a photo of a cemetery that is quite famous.
The photo;
http://www.fada.com/view_image.html?image_no=3543
And the artist;
http://query.nytimes.com/gst/fullpage.html?res=9E0CE3D91439F933A25752C1A963958260
If I remember right, the story, as told by his daughter, goes that Ansel was driving down the highway at sunset and the light caught his eye. He pulled over and set up his camera with barely enough time to calculate the exposure and took the shot while the wife and kids waited patiently in the car. My point is that graveyard shots were probably just as -likewise- then as they are now and that the man picked out a great scene because of his trained eye, regardless.
I'm not that talented when it comes to picking shots hauling-ass down the California freeways. I've seen this shot in my head for several of the last six years since I've been to the site. I got lucky here in that despite my fooling around and was about an hour later to the location than I should have been to setup and relax, that I pretty much knew what I wanted walking up to it. It's not an ordinary graveyard.
The horizon is what it is. The site is located about midway up what is called a bajada (Spanish pronunciation - ba-ha-da), which is basically a broad slope at the base of a canyon, or more often, several canyons as alluvium/gravels gather and spreads. A long even slope. Although there is a lot of talk about the -flat- featureless desert, an even, straight horizon is pretty much rare. What I did do, since I didn't have my level (I was late I hadn't the time to setup on the tripod and lug it around shot to shot), was line up vertically on the little dark cross in the foreground.
Here's another shot where the only thing to square up on was the predominate vertical line of the cholla (choy-ya) cactus on the left. How about that horizon?

If you're wondering (and 'cause I'm kind of bored) the 'bubble' is caused by volcanic pressure that cooled before it could errupt, just pushing the surrounding area up.
But most of all, thank you! I'm glad you like the shot.