Its accelerator complex has evolved over nearly half a century.
Soon CERN's flagship accelerator, the Large Electron-Positron
collider, LEP, will be dismantled and the Large Hadron Collider
or LHC, will be installed in its place in a tunnel, 27 kilometers
in circumference, deep underground.
The LEP/LHC ring is marked by a large white circle. Geneva airport's
4 kilometre long runway, visible in the foreground, gives an idea
of the scale of CERN's mighty machines.