Looks like only the Army`s Nike Missile-Master blockhouse and the Air Force Power-Plant building now remain.
Compare to the vintage aerial photo at http://www.radomes.org/museum/photos/ArlingtonHeightsAIILaerial.jpg (that photo is looking southeast; the NE corner of the Missile-Master blockhouse is seen on the far right).
Above views looking North
Above views looking East
Above views looking South
Above views looking West