How to check into my room on arrival?

- CERN Hostel in Meyrin (Switzerland): If you arrive within the hostel reception's opening hours (Mon-Fri 7:30 am to midnight  and Sat-Sun 9:00 am to midnight) you should go to the reception of building 39 to get the keys to your room. If you expect to arrive later than 12:00 am, you must inform the Hostel Reception in advance and specify your time of arrival. Room keys can be obtained from the security guard on duty at the entrance to CERN's Meyrin site - Gate B (building 533). They will also give you a map of CERN.

- Saint-Genis Hostel (France): In Saint Genis, the check-in is possible only between 15:15 and 19:00 weekly. If you arrive outside of these hours you should go to the CERN site in Meyrin (you must inform the Hostel Reception in advance). If the reception of building 39 is open, they will give you the keys to your room in Saint-Genis, otherwise, if the reception is closed, room keys can be obtained from the security guard on duty at the entrance to CERN's Meyrin site - Gate B (building 533).

See here for more information on the CERN housing service.