CERN is open to everyone but receives about twice as many requests for places on guided tours than it can accommodate.

Guided tours for individuals (less than 12 visitors) can only be booked on site, upon availability and maximum two hours in advance .
Groups (12 visitors and more) can book guided tours in advance. They should be booked as early as possible (i.e. 9 months in advance).

Even though outreach and guided tours are part of CERN’s key missions, its main mission is fundamental research.

Therefore, budgetary, technical and safety constraints limit the number of people who can visit the Laboratory. Nonetheless, CERN welcomes more than 150,000 visitors each year on guided tours, in addition to visitors to our free exhibitions). The Visits Service makes sure that tours are distributed fairly between nationalities, languages, age groups, etc.

If you cannot get onto a guided tour, here are some alternatives:

• Try another date
• Visit one of our exhibitions, which are a very good way of finding out what CERN looks like from the inside. Admission is free of charge and no reservation is needed.
• Attend one of our public events
• Check our online resources as well.

Thank you for your understanding!