The brigs in Atlantis are used to lock dangerous people away. The brigs are rooms which have a cage in the middle. This cage is not only protected by horizontal running bars but also by a powerful force field which no one can penetrate. These fields only drop when the chamber is unlocked.

Atlantis houses a huge number of laboratories in which the Ancients were conducting many different experiments. Over time the Atlantis expedition stumbled upon some of them. Some of these rooms are now used by the Atlantis expedition, but most of them are unused and unexplored.

The Armoury houses the weapons used by the Marines, SGA teams. Everything from handguns to p-90's and explosives are stored here. Guarded at all times by a fully armed Marine guard.

The Marine Detachment is quartered here. There are several training rooms, an open area for assembly and drill and even a firing range setup in this area of the city.