The Altar[]
"In the forest, I stumbled upon an enormous structure. It seemed as if it belonged in a Fritz Lang movie, but it exuded far more malevolence. I managed to deduce how it worked. Its four towers draw psychic energy from the square. A heart encased in a machine converts the energy into another substance and feeds it to the altar in the rear. Is it some device for a religious ritual? And what does the female statue behind the altar represent?"
— Detective's Tapes #18
Location:
- In the area where you need to destroy the 4 towers you will start off facing the altar. the tape is to your left near the wall. (Act 5)
Follow this video walkthrough for more details: