The transport system in Paris...

• How to go to Paris
  This is actually a bit more difficult than you might expect. You have several options, but the main goal is to get to the RER B. To do so, you can either: take the bus 9 at "Joliot Curie" or "Moulon" (both stops being on campus) until "Gare du Guichet" where you then take the RER B to go to Paris, or take the 91-06/91-10 to go to Massy-Palaiseau and take the RER B there.
  We know it is pretty difficult to navigate and remember, so we recommend you install CityMapper to help you navigate in the region.
• Warning ! Timetables
  The buses in this region have a tendency to change their timetable when you need them the most. Jokes aside, pay close attention to when your bus is supposed to pass. For instance the bus 9 that is the recommended way to go to Paris and come back only passes every half hour after 8pm or 9pm. So be careful or that.
• Is there anything around the campus ?
  It might not seem like it, but in fact there is ! If you take the 91-06/91-10 towards Massy-Palaiseau, you'll reach the other part of the Paris-Saclay campus where the 'École Polytechnique" is located as well as others engineering schools and a few shops.
  There are other places you can reach, like Gif-sur-Yvette by taking the bus 11, or Orsay by taking the bus 7.
• Is there a shopping centre anywhere ?
  Yes ! It is located in "Les Ulis", and if you go to the page Useful Places you will find a map showing the Carrefour in the shopping centre. To go there, you either need a car or to be willing to endure 45 minutes of the bus 9 (at least) both ways.