The Seveso is sometimes called il fiume nero, or "the black river," on account of the colour it acquires from industrial pollutants.
The 'Oltreseveso' is the area in the north-west of Lombardy, (it is ‘oltre’ (beyond) the Seveso river). The beyond Seveso brianzolo, ( of Brianza), consists of the municipalities of Cermenate, Lazzate, Misinto, Cogliate, Ceriano Laghetto, Solaro and Limbiate.