Travel to Orsay
From the airport
LAL and IPNO are located on the Université d’Orsay Paris-Sud Campus, 25 kilometers south-west of Paris. The easiest way to reach the Orsay campus is by taking the RER B line to the Orsay-Ville station (35 minutes from Châtelet, around 4.45 € for a single ticket and 1 hour from Charles de Gaulle).
From Charles de Gaulle airport
RER station is located at « Roissypole », linked by CDGVAL light rail.:
- From Terminal 1:
The RER station is not located inside Terminal 1. Take the CDGVAL light rail (5 minutes journey) to « Terminal 3- Roissypole ». CDGVAL station for Terminal 1 is located at level 2; - From Terminal 2:
RER station is underneath Terminal 2, between Terminal 2C/2E and 2D/2F. Go to the rail station by walk (look for « Paris by train » or « Gare » signs) or board free shuttle bus; - From Terminal 3:
The RER station is not located inside Terminal 3. Look for « Paris by train » signs (follow the signposted footpaths). RER station is 400 meters away from the terminal (5 minutes journey by walk) .
At the RER station, take the RER B going to Saint-Rémy-lès-Chevreuse (and not to Robinson), getting off at Orsay-Ville.
The price for a RER ticket from Roissy-Charles de Gaulle to Orsay-ville is 14,05 €.
Take the Orlyval at the price of 11,85 € (Automatic rail link connecting to RER line B) to the Antony station and then transfer to the RER B going to Saint-Rémy-lès-Chevreuse (and not to Robinson) and get off at Orsay-Ville.
Tips (You will find maps, time tables, etc., about metro and RER here.
Please do not mistake the RER B station « Orsay-Ville » for the Paris metro station « Musée d’Orsay ». From Paris, you must buy a ticket specifically for « Orsay-Ville ». A Paris metro ticket is not sufficient !.
There is a special ticket called « ParisVisite » .
It comes as a card with a coupon attached and opens the doors to the whole Ile-de-France network : Metro, RER, Buses, Trams, SNCF overland suburban trains. How about a few destinations ? – Disneyland Resort Paris (zone 5), the Château de Versailles (zone 4), Orsay-Ville (zone 5) or the airports at Charles de Gaulle (zone 5) and Orly (zone 4). The pass becomes valid from the first day of use (and not when you buy it). Once you have bought your ParisVisite pass, fill in the card with your name and first name. Take care to write the serial number of the card on the coupon and add your planned start date. The card and coupon must be kept together and produced for inspection when requested. The price for Three days (Zones 1-5) is 53,75 € (65,80 € for five days).
From train stations in Paris 
The main train stations (Gare du Nord, Gare de l’Est and Gare de Lyon are connected to the Metro/RER system going to Orsay-Ville. Consult the preceding paragraph for fares (coupons etc).
By road from Paris
If you leave Paris from « Porte d’Italie » or « Porte d’Orléans », take the A6 autoroute in the direction of Lyon ; on the autoroute, after 10 km, follow in the direction of « Bordeaux » ; after another 10km, take the Orsay exit and follow panels to reach Orsay and « Faculté d’Orsay ». After this, look up in a local map to find LAL and IPNO.
If you leave Paris from « Pont de Sèvres », take the N118 in the direction of « Bordeaux », after 30 km, exit at Orsay. Then, follow « Faculté d’Orsay » or find the RER-B train station « Orsay-Ville ». After this, look up in a local map to find LAL and IPNO.
In principle, going to Orsay from Paris in the morning is « against the flow » : « pros » do the trip in 30 mn ! (Speed is limited to 110 km/h on autoroute, 90 km/h on national roads, 50 km/h in town).
At Orsay 
From the station RER B « Orsay-Ville »
Exit station and to the left take the pedestrian tunnel that crosses back under the railway (follow the students) go down « Rue E. Desjobert », following the « Orsay University » arrow.
