LHC Accelerator

I worked @ CERN, the European Center for Nuclear Research, during 2007. Really impressive. This is the biggest particule accelerator in the world - still under construction at this time (January 2008). 27 kilometers of ultra-high vacuum tubes, thermal insulation and -271°C liquid helium pipes, 100 meters below the earth surface. Jaw dropping.

Oh, and access will be restricted to very few people after the machine will start, due to induced radiation. So I am one of the few people on Earth who have seen with their bare eyes this incredible machine.