>> they would ceremoniously enter the chambers adorned, lamp lit. one of the most sacred spots in the ancient city. >> and you see the thermal water coming here. >> i see it. yeah. people came here without eating, without drinking, and all the gas gave a change of perception in the minds. >> they go into this altered state? >> yes. altered state to have a dream, and after this dream came the healing. it's not possible to heal without the mind. they are strictly connected. >> the ancients practiced the psychedelic right as late as the 12th serccentury. they figured out something profound. healing can be as much about healing your perception of pain as much as the pain itself. it's the experiment with lsd to