I think the most dangerous city in Europe is London, i felt insicure over there, especially at night
I visited London a few times, because i had close friend living there, there a lot of low-lifes in London who will pull up a knife and rob you. In general you are pretty safe in London, but there are parts of city you want to avoid, for example south London.
I lived near King's Cross Station for 6 months and it wasn't very safe, but yes, it depends on the area
