You can but tickets for one, two or three days, depending on your stamina and the quality of the lineup. For the seasoned festival-goer, camping space is available to set up a tent on the premises. In any case, if you're looking for a good outdoor music festival during your summer sojourn in Paris, make sure to reserve a day or two for Rock en Seine.
Rock en Seine 2013 Practical Information
Dates: August 23rd-25th, 2013
Location: Domaine Nationale du St-Cloud, St-Cloud (just west of Paris)
How to Get There: The terrain is just five minutes away on foot from Metro Boulogne-Pont de St. Cloud (Line 10:Gare d’Austerlitz/Boulogne–Pont de St-Cloud). You can also take the T2 tramway line to Parc de St-Cloud, or bus number 160, 175, 460, 467, 52, 72 or 126 to Parc de St-Cloud or Pont de St-Cloud.
How to Buy Tickets to Rock en Seine?: Visit the booking page at the official website (in English)
Camping Out at the Festival: See this page for more information. Note that you must reserve a campsite in advance-- you won't be able to do so during the festival.
Contact Rock en Seine for more information: Send an e-mail to firstname.lastname@example.org