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Please read this page carefully, especially if you have never been to CEA Saclay.  You may wish to print this page or save it as a PDF for use during your travels.  It was last updated on 10 June.

Getting from Paris to Le Guichet:
Take the RER B commuter train south and get off at "Le Guichet" station.  A schematic of the RER B line can be found here.  You will need to purchase a ticket specifically for Le Guichet (Zone 5) from a machine or ticket booth at any Metro or RER station.  To save time, considering buying 3 roundtrip tickets on Monday morning or already when you arrive on Sunday evening; the total cost will be 24.60 EUR.  Note that not all trains go as far as Le Guichet, so be sure to only get on a train with destination "Saint-Rémy-lès-Chevreuse" or "Orsay-Ville".  Regardless, be sure the stop "Le Guichet" is indicated.  These run every ~10 min.  The exact schedule can be found here.  The travel time from e.g. station "Saint-Michel Notre-Dame" in Paris is ~35 min.

Getting from Le Guichet to CEA Saclay:
A shuttle bus will pick you up near Le Guichet RER B station each morning.  A map and walking directions to the shuttle bus can be found here.  It will depart at 09h00.  Please plan to arrive well in advance since the RER B line is often delayed 5-10 min with respect to the official schedule.  We will monitor the state of traffic and if there is a significant delay the shuttle bus will wait for you to arrive.  From Le Guichet, it is just a short 10 min ride to the workshop venue at CEA Saclay's Service d'Astrophysique.

Getting from CEA back to Paris:
Essentially the reverse: the shuttle bus will return you to Le Guichet station every evening at approx. 18h.   From there, there are regular RER B trains back to Paris.

What if I miss the shuttle bus or my travel plans are different?
- Public bus line 9 stops at both "Gare du Guichet" and "Orme des Merisiers" (across the street from the workshop venue).  The schedule can be found here.  You can buy a ticket from the driver.
- Public bus lines 91.06B, 91.06C, and 91.10 stop at both "Massy-Palaiseau Gare RER B" and Orme des Merisiers.  Do not get off at the stop called "CEA Port Nord"; we are not very close to there actually.  The schedule can be found here.  You can buy a ticket from the driver.
- Taxi.  There is a taxi stand at Le Guichet.  Or you can call +33 1 69 28 40 07.  Tell them you need to be picked up / dropped off at "CEA Saclay, l'Orme des Merisiers, Saint-Aubin".  If you have difficulties (e.g. they may not speak English well), please let us know in advance and we can arrange a taxi for you.

Coming by car:
If you're arriving by car, directions can be found here.

Traveling to/from Orly Airport:
The Orlyval metro is currently under construction, but there will be shuttle buses that also make the connection between Orly Airport and the "Antony" RER station.  You may also take the 91.10 bus (see above) from Orly Ouest directly to Orme des Merisiers.  Please see this PDF for more information.

Please book your hotel as soon as possible since hotels book up quickly especially in Paris in summer.
We recommend you reserve a hotel:
- in Paris: near any RER B station.  The area around Saint-Michel Notre-Dame (the Latin Quarter) is quite popular.  There are countless options; please see your favorite website, or this handy list of hotel recommendations.
- in Orsay: near Le Guichet RER B station, if you want a shorter commute and don't mind being outside Paris.  You should know that the area is very quiet with virtually nothing to do or see in the evenings.  Hotel d'Orsay (**), ~70 EUR/night.  You can book directly or through any third-party website (e.g.

Getting around in Paris:
You may find these websites helpful: Vianavigo, RATP

You must bring a valid passport (or national identity card from a European Union member country) with you at least on the first day, in order to get your CEA Visitor security badge.  A driver's license is not sufficient.

A mobile phone contact will be sent to you by email before the workshop in case you have any urgent problems.