Well, the actual objective point would be a specific spot next to it, let's say the immediate rear point, to represent the entrance hatch or an external panel of some variety. Other than that, objectives could include destroying it (attackers only) and set specific rules to avoid the attacker going "artillery to BOOM BOOM BOOM!" such as a void shield making attackers only within a certain area able to hit, etc. I dunno, I like objectives having actual visual and narrative purpose beyond "this spot in the open, completely exposed and with no landmarks is vital for the battle, secure it". I get that for balanced gameplay, especially in tournies, it's needed, but then I have no desire to participate in competitive tournaments, I like my narrative play. ;-P So many things I've seen but haven't bought that would be amazing scenery. There was an artillery railcar that I saw once, and immediately thought it would make a good centrepiece around which a battle could be fought. Heck, I would buy an entire railway model set for scenic purposes if I could afford it. Don't even need to buy or print warhammer-ified trains, would work as is. XD
I'm using a train of my sons as terrain, when he's not using it. It doesn't hurt that it's the right scale or that it's a military train.