Madrid for some reason does not have really bad districts. The only place that springs to mind as places you would DEFINITELY not want to go is the “Cañada Real”, which is a kind of shanty town south-east of Madrid. And possibly, from what I have seen, San Cristobal in Villaverde and maybe certain parts of Tetuan. read more
The South of Madrid is awful with a lot of bad neighborhoods. There are trendy neighborhoods downtown like Chueca and Barrio de las Letras, Justicia with some good streets and bad. The good neighborhoods outside Madrid are La Moraleja, Villafranca del Castillo, Boadilla del Monte, Las Rozas, Majadahonda all with modern condos with pools and shopping centers. read more