The Large Hadron Collider (LHC), a 27 kilometer (17 mile) long particle accelerator straddling the border of Switzerland and France, is nearly set to begin its first particle beam tests. The European Organization for Nuclear Research (CERN) is preparing for its first small tests in early August, leading to a planned full-track test in September - and the first planned particle collisions before the end of the year. The final step before starting is the chilling of the entire collider to -271.25 C (-456.25 F). Here is a collection of photographs from CERN, showing various stages of completion of the LHC and several of its larger experiments (some over seven stories tall), over the past several years.

View of the CMS (Compact Muon Solenoid) experiment Tracker Outer Barrel (TOB) in the cleaning room. The CMS is one of two general-purpose LHC experiments designed to explore the physics of the Terascale, the energy region where physicists believe they will find answers to the central questions at the heart of 21st-century particle physics. (Maximilien Brice, © CERN)