From Terminal 2 : Go directly to the RER station
From Terminal 1 : Take the bus shuttle to Gare RER.

Take RER line B direction Saint Remy les Chevreuse. Check on the platform display that the train is going to Orsay Ville

Duration : 1 h 20 mn

Buy a ticket for Orsay Ville at the Orly airport Orlyval Station.Take the OrlyVal train to Antony (follow the signs Charles de Gaule Airport). At Antony, take the RER line B south, direction Saint Remy les Chevreuse, and follow as below.

Duration : 50 mn

Join any RER B station, and take a ticket for Orsay Ville. Take the RER line B towards Saint-Remy les Chevreuse. be careful not take a train heading toward Robinson. Exit at Orsay-Ville.All trains do not stop at Orsay-Ville. Make sure that your train stops there by checking the information displays at your boarding station.

From RER to IAS

From Porte de Saint Cloud (south west):

take the N118 High Way, direction CHARTRES, take ORSAY exit, first turn on the right, at the traffic light, go straight ahead, on a few hundred meters.
After the RER station (on the left of the road), the road turns on the right, towards the main University entrance gate. Before the gate, turn on the left , rue Jean Teilhac.
Three or four hundred meters down, IAS is Bat. 121, on the left, with green windows. Park your car on the right.
The main entrance of the IAS building is on the top of the stairs, on the left.

From Porte d'Orléans (south):

From the périphérique (beltway), follow highway A6 south, direction LYON. Exit towards Palaiseau. Stay on the right. Follow the signs to Highway A10. Exit at Orsay-Bures. Follow the little road for a few miles and exit at Orsay. Follow of highway for 200 meters and take the first exit. Turn right at the roundabout and follow straight to the traffic light. Go straight under the RER bridge. After the RER station, take the first left (rue Jean Teilhac) and follow straight until you see the 'Oui a Soleil' sign. IAS is on your left.

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