Pontoise is the official préfecture (capital) of the Val-d'Oise département, although in reality the préfecture building and administration, as well as the department council (conseil général), are located in the neighboring commune of Cergy, which is regarded as the de facto capital of Val-d'Oise.

The sous-préfecture building and administration, unlike the préfecture, are located inside the commune of Pontoise.

At that time, the rock peak overhanging the river Oise supported the defense of the fort which was on the Roman road, the Chaussée Jules César, between Lutetia (Paris) and Rotomagus (Rouen).

With an over 2,000 year legacy, Pontoise still has vestiges of the past, such as medieval lanes, convents, churches and museums, and was awarded the "City of Art and History Label" in 2006.

2 An immigrant is a person born in a foreign country not having French citizenship at birth.

For bus services, Stivo (formerly Services des Transports de l'Agglomération Nouvelle) operates within the new town of Cergy-Pontoise, and in and around Pontoise, with transport interchanges situated Place Charles de Gaulle and Parking Canrobert.