Scully and Mulder watch Tooms where he is being held in a mental hospital in episode #103 "Squeeze".
Mulder and Scully enter a secure psychiatric facility to question Eve 6 about the cloning program in episode #111 "Eve".
Appears as the military base in Caledonia Capital City in episode #915 "Ethon".
The hospital where Rodney and his sister were held in S4E9 episode Miller's Crossing.
Episode #306 "The Real World".