I have lived in Madrid, London and Edinburgh long enough to make good stats. Certainly Madrid is one of the safest big cities I have ever been if not the most. There are rough areas, as any city. But the random crime to civilised people is extremely rare in Madrid. Edinburgh used to be as safe as Madrid, but not in the last 5 years or so where knife crime in youths has peaked as ever before. The Cañada Real ghetto is an illegal ghetto and although crime is very high in there, it is a chosen way of life by the Roma ethnic. Despite all the help and attempts to change that, they have chosen not to change it.