DOWNTOWN LOS ANGELES — The terrain of Downtown Los Angeles fascinates me. It's definitely not flat, as anyone who's walked up to Bunker Hill can tell you. Looking at Downtown via a flat road map doesn't give you any sense of its complexity: Downtown has two Grand Avenues, two 2nd Streets, two 3rd Streets. 4th Street goes from the 110 to Olive without touching "street-level." Basic terrain models (such as the pictured one from Google) are simply wrong in placing Downtown on a smooth change.

And yet these days it seems to me that much of this elevation is artificial. Sure, Downtown was at one point built on a hill, but today the streets and foundations have so punctured this natural landscape that very little of it remains.

It seems to me that the only vague remnants of Downtown's original shape are the roadways like upper Grand. Upper Grand is like the metal band that goes around a barrel, only the wood's now gone. It traces the contour of a street, but not on ground. Buildings go along with the lie, giving it their public fronts. Underneath, on the real level of the "ground", is the commercial underbelly of loading docks and parking structures.

But it's not just Grand. How many of the buildings between 5th and 2nd actually have their base on the level of the street? The YMCA sits on the level of Hope, but its roots front Flower many feet below. The Bonaventure doesn't even have a hill, but its skyways create an artificial ground level far above the streets.

I would love to see a 3d model of what Downtown's topography would look like if you removed all of the buildings -- including foundations. Would it be flat? Would it look at all like what you see outside? Obviously tools like Google Earth with mathematical topographic models are useless for something like this. Where would you find accurate data for something like this? Bureau of Engineering?