Cogels Osylei

Art nouveau street, unique architecture from around 1920. The street is located outside of the city centre, near the Berchem train station (where the international train Brussels-Amsterdam stops).
There aren't any buildings you can go in, but it is great to stroll through the street and the side streets (Waterloo street, Transvaal street) where you will find many great buildings and villas.
There are some nice bars and restaurants in the neighborhood too.