There is a park up the hill of Bergen (quite close to the center), that should be really avoided, especially in the evening or night. One of my friends lived there while studying and was attacked by a drug addict. I was walking the street at 6p.m. and also saw lot of junkies, taking their pants off and injecting just in the street. There were three robberies during my stay (one week) in the appartments around this park. I don't know why the police is not taking care about this district. Strange.
If you arrive in town, are tired, and have to walk more than one or two blocks to your hotel with your bags, consider hailing a taxi. I came in by ferry, and my B&B was up near the university. While it wasn't far, those 'quaint' hills became quite a challenge with a couple of heavy suitcases (and it started raining to boot)!
Woman.. ! Dont use your high heals shoes.. !
You can be caught ... Not by the Norwegian men, but by the brick stones in the street..