- You may be looking for the moon.
The European Organisation For Nuclear Research, known as CERN, was, according to the Twelfth Doctor, the largest particle physics laboratory on the planet. (TV: Extremis) It was located in Switzerland. (AUDIO: Lost Souls)
CERN housed the Large Hadron Collider, which allowed neutron eaters to escape into N-Space and kill humans. Torchwood Three, along with some CERN staff and UNIT's Martha Jones, managed to defeat the neutron eaters and save CERN. (AUDIO: Lost Souls)