Large Hadron Collider (LHC)

http://public.web.cern.ch/public/en/About/About-en.html. CERN, the European Organization for Nuclear Research, is the major global facility for particle physics, and is based in Geneva. Member states involved in it are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a candidate for accession, while Israel and Serbia are currently associate members as part of the pre-stage to full membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have been granted observer status.

Taken from http://en.wikipedia.org/wiki/Particle_physics and links given therein.