Guyancourt (French: [ɡɥi.jɑ̃.kuʁ] (listen)) is a commune in the Yvelines department in the Île-de-France region in north-central France. It is located in the south-western suburbs of Paris, 21.2 km (13.2 mi) from the center of Paris, in the "new town" of Saint-Quentin-en-Yvelines.
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