A Bird's Eye View of the LEP Site.
LEP (Large Electron Positron Collider) is an accelerator built by the CERN Laboratory at the border between Switzerland and France. The accelerator ring is aligned inside a circular tunnel of a 27km circumference located 100m below the ground. LEP accelerates electrons and positrons to the world's highest energy and collides them at four experimental areas, where four experiments (ALEPH, DELPHI, L3, and OPAL) measure the reactions.
