Seattle would have looked a lot more like San Francisco today if the city leaders hadn't decided to smooth out a lot of the hills downtown. Low areas were raised by building a new street level, sealing off the original ground floors and creating Seattle's famous underground. High points were blasted with fire hoses and dumped into Elliott Bay via various sluiceways and conveyors. Hundreds of structures were either moved or destroyed. It took decades to complete and the result is a town that is... uh... well, still pretty damned hilly. Here are some regrade photos juxtaposed with the present day.
Looking towards King St. Station (the little pointy thing in the middle) in 1909. The original was shot more to the left (closer to Weller St.), but this still works pretty well. Seattle was pretty apocalyptic looking for some time.
A freshly regraded view of 4th in 1909 vs. the same intersection today
Denny Hill as seen from 2nd and Pine, with the soon-to-be destroyed Denny Hotel. The hill was slightly more to the right, but I had trouble lining up the shot.
A before and after at 6th and Marion with buildings from 1914.