Outside of the giant volcanos (like Olympus Mons), are there any really high mountains on Mars? The hills that the Mars rovers have photographed are really pretty low and rounded off. Have there been real mountain ranges on the planet?
Nars seems a pretty flat planet-is it because there were no plate tectonics (as on Earth)? 
Huh? Why isn’t Olympus Mons a “real” mountain?
You might take a look at this:
http://en.wikipedia.org/wiki/List_of_mountains_on_Mars_by_height
Rumor has it that Mars did have plate tectonics for the first half billion or so years of it’s existence.
After 4.5 billion years, any resulting mountains are probably gone. However the southern highlands and pole are still nearly 4000 meters above the average surface.
In support of your argument, maybe, even Olympus Mons seems to be very broad and flat, not pointy like our Earth mountains and volcanos get.
Yup. Mars has not experienced the effects of plate tectonics in a long time. Hence, all (I think) Martian mountains are either volcanos or the result of impacts.
Of the volcanos (all of which appear inactive), Olympus, Pavonis, Arsia and Ascraeus have reached the isostatic limit - the height at which their weight is balanced by the strength of the crust below. Hence, they are all at approximately the same height, which is the maximum possible for a mountain on Mars (ignoring variation in crust thickness and composition). Olympus is wider than the others, winning it the title of the largest mountain in the solar system.
Large impact craters create rims on the same scale as mountain ranges. I believe that at least one of the rovers is inside a crater and that the hills we are seeing are the rim. They are a long way off because the crater is pretty damned big - NASA had to pick an easy target to land in.
The landing in a crater was not planned, and was a happy accident. That rover has long since climbed out of it.
I’ve merged ralph’s two threads, in case you wonder why things look funny.
samclem
He’s not talking about the small crater the rover landed in but the huge Gusev Crater, which was the target of the rover. The small crater it rolled into is within Gusev.