Big MT

The Big Empty (Big Mt. Training Facility) is a place that after the Great War is being run by Mr. Handy robots.

Appearances
Big Empty did not appear in any of the published games, but was to appear in the canceled Fallout 3 project by Black Isle codenamed Van Buren. It is also mentioned in Fallout: New Vegas add-on Dead Money.

Behind the scenes
At some point during the development of Van Buren, Big Empty was merged with the Leavenworth prison into what became the Tibbets Prison, which was still referred to as "Big Empty" by some of the developers. It is currently unknown whether the mention of of Big Empty in Dead Money refers to the pre-merge version of this location, or to Tibbets.