East of the cliffs of the Emyn Muil, the Dead Marshes were also known as the Mere of Dead Faces. Gollum leads Frodo and Sam this way to avoid the plains before the gates of Mordor as they were crawling with his servants. He had travelled this way before, when escaping from orcs, and knew a route through. Once the graveyard of men, elves and orcs who died in battle, the marshlands flooded in the change of climate following Sauron's resettlement of Mordor, and the graves were disturbed, transforming it into an evil and haunted territory. Great black pools appeared, crawling with evil life, although no birds would enter the marshes. Lights like candles flickered in the dark of night, and in this light it was said that the faces of the dead could be glimpsed in the water. Gollum had tried to reach the dead faces, but they were beyond his reach. The lights enticed travellers, and they might be tempted to gaze into the pools, whereupon they would fall in and become trapped amongst those killed in long ago battle. Sam prevents Frodo from become bound by their spell, but trips and finds himself face to face with the dead.