Pontoise is the official préfecture (capital) of the Val-d'Oisedépartement, although in reality the préfecture building and administration, as well as the department council (conseil général), are located inside the neighboring commune of Cergy, which is regarded as the de facto capital of Val-d'Oise.
Pontoise is the historical capital of the Vexin français. Its foundation dates from the Roman times (Pontisara). At that time, the rock piton overhanging the river Oise supported the defense of the ford which was on the Roman road, the Chaussée Jules César, between Lutetia (Paris) and Rotomagus (Rouen). The road still exists and is now part of the N14 from Paris to Rouen. A famous religious sister, Blessed Marie de l'Incarnation (1566-1618), formerly known as Madame Acarie, the foundres of the Reformed Carmelites in France, lived, died and was buried here in The Carmelite Monastery.
¹This group is made up largely of former French settlers, such as pieds-noirs in Northwest Africa, followed by former colonial citizens who had French citizenship at birth (such as was often the case for the native elite in French colonies), and to a lesser extent foreign-born children of French expatriates. Note that a foreign country is understood as a country not part of France as of 1999, so a person born for example in 1950 in Algeria, when Algeria was an integral part of France, is nonetheless listed as a person born in a foreign country in French statistics.
²An immigrant is a person born in a foreign country not having French citizenship at birth. Note that an immigrant may have acquired French citizenship since moving to France, but is still considered an immigrant in French statistics. On the other hand, persons born in France with foreign citizenship (the children of immigrants) are not listed as immigrants.
Cathédrale Saint-Maclou de Pontoise. It was built in the 12th century and reconstructed and enlarged in the 15th and 16th centuries. The tower as well as the central portal is in flamboyant style .The central body is flanked by Renaissance additions. The remaining 12th century part of the cathedral is to the back. To the North of the building is a Renaissance portal.
Musée de Pontoise (Musée Tavet-Delacour). The museum houses sculptures from the Middle Ages, manuscripts from the seventeenth century and paintings from the twentieth century