In Amsterdam, it can take a somewhat trained eye to even know you're in the "bad" part of town.
First, there's the immigrant issue. Actually the issue is more with the children (the male children) of immigrants. Immigrants, and not just illegal immigrants, are considered a problem here and in most of Western Europe. Citizens of Moroccan decent take most of the blame here. Some--but not all--of it deserved.
Here, for instance, are three youths blocking the bike path. Just because they can. Dudes, you're so cool. So tough. So I had to bike around them on the grass.
Then there's this picture:
To an American, it probably looks innocuous. But to many Dutch people, this gives reason to not want to live in the neighborhood.
It's not the blah architecture. Or the largely failed suburban vision in an urban area. It's the satellite dishes. In Holland, many people consider satellite dishes a blight and a figurative "Broken Window." They're aimed at Turkish and Moroccan TV stations. It means the residents aren't really "Dutch." It means there are more mosques than churches. It means the crime rate is higher. It means there are troublesome Moroccan youths hanging out. At least that's how it's seen.
It should be noted that even in the "bad" part of town, there's a pretty canal to stroll down.(that's my brother posing)
And more desirable middle-class--even upscale--housing being built across the street.