The LHC (Large Hadron[1] Collider) is located in France and Switzerland at CERN[2]; the first experiments begin in early August 2008 and a full test of all 27km of track is planned in September. Project members expect to be analyzing the first collisions by the end of the year. The entire track will be cooled to just 1.75ºC shy of absolute zero (to -271.25ºC) and will be in-use for decades. The big expectation is that the long-sought Higgs Boson[3] makes an appearance.
The article Large Hadron Collider nearly ready (Big Picture) has dozens of high-quality images showing this incredibly large-scale machine.