You won't find a neighborhood in Seattle that's changing right now more than Denny Triangle. The heart of Central Seattle is in the midst of a construction boom that will eventually render it completely unrecognizable from what it once was.
This certainly isn't the first time this area will have gone through such a massive change. While this region is pretty much flat terrain now, it used to be a steep land mass known as Denny Hill. As a way to make it easier to develop, that hill was systematically taken down as part of what has become known as the Denny Regrade project. One of many regrades through the city, Denny Regrade No. 1 took down everything between Fifth Avenue and the waterfront between 1902 and 1911. Then in 1929–30, Denny Regrade No. 2 took out the remaining pieces of the hill east of Fifth Avenue by use of steam shovels.
Looking at photo from the era, it almost seems at times as though you're looking at the Mars terrain or some strange Wild West topography of an uninhabited land. It almost makes you wonder why early settlers thought stopping here seemed like such a good idea in the first place. Though clearly even if it didn't look like it made sense, Seattle ended up bending the land to it's own will to become the city we live in today.
· Regrading in Seattle [Wiki]