The Centre de Mathématiques Appliquées de l’X is located within the campus of Ecole polytechnique, in the labs area. The Ecole polytechnique is located in the south suburb of Paris. To get there, you may come by RER or by car.

By RER

RER B + Walking

take RER B4 towards Saint Rémy-lès-Chevreuse and get off at Lozère ;
when leaving the RER station, take the underground passage to cross the tracks ;
take the road to the left of the restaurant, then climb the steps leading to Ecole polytechnique (approx. 10 to 15 minutes) ;

RER B, C or TGV train station MASSY + Bus

Get off at the Massy-Palaiseau station and take the Bus TransEssonne n° 91-06 (B or C), whose stop is located close to the footbridge between the TGV station and the RER B station. Get off at the stop "Laboratoires" of Ecole polytechnique.

By car

 Pont de Sèvres, N118 towards Chartres-Orléans, exit at Centre Universitaire, towards École polytechnique ;
 A6a or A6b towards Chartres-Orléans, exit Saclay, Versailles, towards Saclay-École polytechnique.

A map of the campus will help you find the "aile 0" in which the CMAP is, on the first and second floors.