On 14 and 15 September, CERN will open its doors to the public from 9.00 a.m. to 6.00 p.m. Held every five to six years, during a Long Shutdown, the CERN Open Days are an exceptional opportunity to discover the Laboratory’s installations and meet the people behind the science and technology. You are one of these people, and you can be a CERN ambassador by taking part in the many planned activities and sharing your personal experiences with the visitors.


Thanks to the fantastic commitment of all departments and many external contractors, more than 150 activities are planned on nine different sites: Meyrin, Prévessin, SM18, LHC1-ATLAS, LHC2-ALICE, LHC4, LHC5-CMS, LHC6 and LHC8-LHCb. Showcasing the diversity of CERN’s science, technology and people, the weekend will provide an opportunity to explore experiments, buildings and sites, to play with hands-on activities for all ages, to interact at talks, debates and shows, and to visit the LHC and its detectors.The complete list of activities is available on the Open Days website. Also, remember that on Friday, 13 September, the CERN community, as well as their families and friends, can register to visit underground sites. There are still a few places available and members of personnel do not need to submit a formal absence request to take part.


You can register as a volunteer until Friday, 6 September. More than 2700 volunteers have already signed up but we still need more to fill the many roles that remain open, especially on Sunday afternoon. Wherever you work at CERN and whatever your regular activities, everyone will have a role to play, from shop assistant to tour guide. More information about roles, shifts and training can be found here.


Outside your slots as a volunteer, you can also attend the Open Days as a visitor. Even if you feel you know CERN well, the event will allow you to find out more about the Laboratory’s activities and meet colleagues from other departments in a friendly atmosphere. Around 30 000 people have already registered for each day, but tickets are still available. Registration guarantees you access to the Open Days and indicates your point of arrival. All activities and visits are then accessible on a first-come, first-served basis, more details can be found here. Remember that places will be limited for visits to the LHC, but there is so much to discover on the surface. If you register as a visitor, please complete the visitor survey before the event by clicking on the link in the registration confirmation e-mail.

Mobility, parking and logistics

With an estimated 30 000 to 40 000 visitors per day, we expect traffic disruption in the neighbouring area. To minimise this, CERN has worked closely with the local authorities to develop parking and mobility procedures. More information about these can be found here. Everyone is strongly encouraged to use public transport, car share, walk or cycle to CERN.

The Globe car park will not be available throughout the weekend (from Friday noon to Sunday 8.00 p.m.), so please plan to leave your car elsewhere. There will be dedicated parking areas for volunteers on each site. These spaces are also available for those of you working over the weekend for the Open Days or the normal running of the Laboratory. You can also use the parking areas for visitors.   

Between 7.45 a.m. and 7.30 p.m. each day, only pedestrian access will be possible on all sites, except for service vehicles, duly identified with a pass. Some parkings reserved for volunteers will be accessible during the day; please check this website.

Safety and the environment

It’s a “safety first” event and considerable effort has been made to ensure the safety and comfort of participants. All buildings, facilities and spaces that will be accessible are being cleared of equipment and made safe for our visitors. Access, capacity and evacuation procedures for visits to supervised areas, especially the LHC and detectors, are in place. There will be more than 90 tents across the nine sites and many kilometres of barriers, to safely guide visitors around the sites.

We care about the environment. Drinking water will be provided and, to avoid single-use plastics, drinks will be served in recyclable “Open Days” cups, available for a small deposit. You are of course free to keep these cups as souvenirs. The restaurants and food trucks around the site have been encouraged to provide drinks on tap.

Digital communications

You can find more details about the Open Days on the event’s website and app. To ensure the event is as paper-free as possible, the app will serve as the main means of communication with visitors. 

If you would like to post about the event on social media, use the hashtag #CERNOpenDays and take note of the social-media guidelines for the CERN community.

Accessing CERN for normal duties during the Open Days weekend

We hope that everyone will want to volunteer and/or visit for the Open Days. However, if you wish to access your usual workspace, you will be able to use your CERN card to access the sites on foot. Please note that access by car to the Meyrin site will be restricted to Gates C and E and only possible before 7.45 a.m. and after 7.30 p.m. on both days. If you have friends and family with you, they should use the visitors’ registration desks and entrances for the Open Days.

Many thanks in advance to everyone for all the work that has been and is still being put into preparing these Open Days and making them happen. It’s set to be an unforgettable event!

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