The LHC is the largest machine ever built and the World Wide Web was created to process its data. It's a 17 mile long microscope which is searching for extra dimensions, the "God particle," anti-matter, and forces akin to those that took place in the first trillionth of a millisecond after the Big Bang at incredibly small sizes on the order of a tenth of a thousandth of a trillionth of a millimeter. It generates a magnetic field more than 100,000 times stronger than the Earth’s and temperature necessary for the LHC’s superconducting magnets to operate is the coldest extended region that we know of in the universe - even colder than outer space. The magnets contain 1,200 tons of superconducting filaments much smaller than a human hair which, if unwrapped, would be long enough to encircle the orbit of Mars. The vacuum inside the proton-containing tubes, a 10 trillionth of an atmosphere, is the most complete vacuum over the largest region ever produced. The LHC uses an amount of electricity required for a small city such as nearby Geneva. The LHC’s $9 billion price tag also makes it the most expensive machine ever built.

Photos taken by both Steve Elkins and his production crew.
An article published by CERN about the January 2012 visit: https://www.steveelkins.net/Interviews/On-Making-ECHOES-OF-THE-INVISIBLE/CERN-Interviews-Steve-Elkins/
An essay by Ben Eshbach about the experience: http://www.beneshbach.com/cern.html