Val-d'Oise is a department in north central France and is part of the region of
Île-de-France. To the south of the department lies the department of
Hauts-de-Seine, to the southwest lies
Yvelines, to the west lies
Eure, to the north lies
Oise, to the east lies
Seine-et-Marne and to the southeast lies
Seine-Saint-Denis. The official
préfecture (capital) of the department is the commune of
Pontoise, situated in the suburbs of
Paris some northwest of the centre of the city, but the
préfecture building and administrative offices are in the neighbouring commune of
Cergy. The
River Oise is a right tributary of the
River Seine, and flows through the province from northeast to southwest. ==Economy==