Some of you may know about the hadron collider - an energy particle accelerator that scientists/physicists built to try to test a bunch of unknown things relating to physics and dark matter and the creation of the universe.
Anyway, I had no idea that the Hadron Collider is as large as it is:
The LHC lies in a tunnel 27 kilometres (17 mi) in circumference, as deep as 175 metres (574 ft)
LHC stands for Large Hadron Collider - quite appropriately named. No wonder people joke about the collider creating a black hole that will suck everything in - it's no small lab gadget.