[The Cajun]

Like the thing that resembles a water pump, with pipe sticking out of it,

That one puzzles the heck out of me.
Looks like a "gun barrel" sticking out of a turret to me, when I first saw it.
Just ain't nothing natural about the "pipe" section.
NASA probably sent the rover away from it as fast as possible, LOL.

[MHGinTN]

The second large face is an interesting thing, too. I want to know what the transparent tubes are. I figure they were water pipes, to use as transportation and transferring water around the planet. May have been pneumatic tubes though ... but they are awfully large in diameter for that.

[cripplecreek]

NASA probably sent the rover away from it as fast as possible, LOL.

Because everybody knows that NASA is desperately terrified of their funding being increased by orders of magnitude if they fund something unnatural.