Take the express subway (RER) ligne B (towards either "Robinson" or
"Saint-Rémy les Chevreuses").
Be sure that the sign « Bagneux » is lip up (never get down at "Arcueil-Cachan" station, you would then have to walk half an hour more !) and get down at
"Bagneux" station. When leaving the station, make a left on the main road until the first traffic light. At this point, you can see the flag at the campus' entrance.