The massive endcap torroids for ATLAS sit at the far end of building 180 (actually 191). For scale, the triangular shaped metal in front is slightly taller than a person.

Ventilation?

One of the endcap torroids in building 191. The vessel contains 8 superconducting loops radiating out, giving it the gear shaped profile. You can see the "little" square loops at each end in [url=http://atlas-magnet.web.cern.ch/atlas-magnet/]t