After sacrificing three Siren Widows, in God of War II, a door opens revealing a pool of water.
Jumping into the water exposes a long swimmable tunnel red with blood. Various bodies are floating around and large spikes protrude from sections of the tunnel wall. Breakable pots are also scattered throughout the flooded passageway. Swimming out of the tunnel leads into the Ice Phoenix Room, where Kratos must solve the puzzle in order to open the door, and proceed to the Arena of the Damned.