The Laboratory is a section inside the Citadel.
The Laboratory is consisted of an Armory, the Lab, the Smithy, a restroom and a mess hall.
The Armory is being held by Durga, a Knight who is in charge of weapons and armor. She will sell weapons and armor to Outsiders... if Elder Owyn Lyons gives allowance.
The Smithy is a section where Scribe Bowditch makes new weapons and repairs old ones.
The Laboratory appears only in Fallout 3.
The mess hall
Duck and cover, light reading for the toilet