Recreational, training, and medical facilities comprise the first sub-surface
level of Avengers Mansion. A fully equipped gymnasium, an Olympic-size pool, sauna
and steam bath are available to the membership, as is a game room featuring a
billiards table, pinball machines, and video arcade games. The Combat Simulation
Room is a heavily reinforced area in which various robotic devices simulating
humanoid and mechanical attacks can be engaged for training purposes. The Combat
Room is monitored and programmed by the mansion's main computer system. Also on
this level are emergency medical facilities, once used by Dr. Donald Blake and
Dr. Henry Pym. There is also a cryogenic storage area in which certain individuals
(members or adversaries) suffering from degenerative aliments can be placed in
Sub-Basement Level One contains the Avengers' high security
Assembly Room where all operational meetings are held. The Assembly Room is the
most secure place in the entire headquarters complex due to its massive reinforcements
and vault like entrance passageway. The first subbasement houses the Avengers'
computer system which contains all of their crime / forensic files, operational
records, and world security data.
Until recently when the Avengers'
governmental security clearances were revoked, the Avengers' computers had limited
access to the national security data of the Pentagon's computer system, as well
as a direct common database with SHIELD. Now the only outside agency with which
the Avengers routinely trade information is the Fantastic Four, Inc. The mansion's
power supply, a thermoelectric generator, along with its attendant back-up systems,
are also housed on this floor, as is the Robotics / Electronics Fabrication Area
once used by Dr. Henry Pym and Anthony Stark. This area is currently used by Dane
Whitman (the Black Knight).
Until recently, Sub-Basement Level Two had been primarily used
for storage. Howard Stark built it for private weapons testing and storage, and
constructed the robot named Arsenal there that would later menace the Avengers.
The Avengers have a submarine pen with its own waterway to the East River, but
with the adoption of the Quinjets as the major means of transit, the submarine
system fell into disuse. In recent months, the submarine pen and waterway has
been refurbished to create the UGABS (Underground Airbase Shuffle) system, a secret
means of rapid transit to the Hydrobase nine miles off the coast of New York.
The shuttle is easily accessible from the assembly Room above, as well as other
parts of the Mansion.