LOCATION@1 is the second most populous commune in the suburbs LOCATION@2 -LRB- after LOCATION@3 -RRB- and by far the most populous commune in the Val-d'Oise department , although it is not its prefecture , which is shared between the communes of LOCATION@4 and LOCATION@5 .

LOCATION@1 is the second most populated town in the suburbs of LOCATION@2 -LRB- after LOCATION@3 -RRB- and the most populated commune in the Val-d'Oise department ; however it is not the prefecture .
