Cergy
Town hall Location (in red) within Paris inner and outer suburbs Location within Île-de-France region Cergy Administration Country France Region Île-de-France Department Val-d'Oise Arrondissement Pontoise Intercommunality Cergy-Pontoise Mayor Dominique Lefebvre (2001–2008) Statistics Elevation 21–121 m (69–397 ft) (avg. 25 m or 82 ft) Land area1 11.68 km2 (4.51 sq mi) Population2 58,265 (2006) - Density 4,988 /km2 (12,920 /sq mi) INSEE/Postal code 95127/ 95000 1 French Land Register data, which excludes lakes, ponds, glaciers > 1 km² (0.386 sq mi or 247 acres) and river estuaries. 2 Population without double counting: residents of multiple communes (e.g., students and military personnel) only counted once.Coordinates: 49°02′10″N 2°03′47″E / 49.0361°N 2.0631°E / 49.0361; 2.0631
Cergy (French pronunciation: ) is a commune in the northwestern suburbs of Paris, France. It is located 27.8 km (17.3 mi) from the center of Paris, in the "new town" of Cergy-Pontoise, created in the 1960s, of which it is the central and most populated commune.
Although neighboring Pontoise is the official préfecture (capital) of the Val-d'Oise département, the préfecture building and administration, as well as the department council (conseil général), are located inside the commune of Cergy, which is regarded as the de facto capital of Val-d'Oise. The sous-préfecture building and administration, on the other hand, are located inside the commune of Pontoise.