This place, although mostly empty, must be visited nonetheless. Its a space for memory. Like the signs say "how can you fill a space, that is already so full of suffering and memory?". I recommend visiting after the Museo de la Memoria; after you have some context of the history and therefore know the relevance of the place. People were kept and tortured there in secret for many years after '73.
good to know: its free to enter, you can book guided tours, you can take pics, and go to the second floor to listen to first hand encounters. read more