Cern, abbreviation for French name Organisation Européenne Pour la Recherche Nucléaire, meaning in English: The European Organization for Nuclear Research, is the biggest, most sophisticated physical research centers in the world, of high significance. It was build and is operated by joint efforts of 21 member countries.
For a tourist it is possible to book a tour to ATLAS. Guided tours are ran by local employees who deeply understand the topic, for free. Tour last about 1 hour. It is mandatory to register for a guided tour more than a week in advance. You only need to find a guide and provide Your name, date of birth. Tours are usually for free.
However, Atlas is closed since October 2014 for about 2 years construction.
Next to Atlas is also an exhibition/museum - big wooden Globe; another exhibition on the other side of CERN is Microcosmos.
There are restaurants 1, 2, 3 and Indian restaurant inside the CERN. Public has no access inside the CERN, only when being accompanied by a local employee. There are several restaurants, cafes and parking lots around.
Bike trail goes 50km around (and above) the LHC circle.