Death Down

From Tolkien Gateway

The Death Down was a hill built by the army of Huorns during the night after the Battle of the Hornburg. In the morning after the battle had ended the dead Orcs of Saruman were piled into heaps near the eaves of the trees in the Deeping-coomb. That night the forest departed. In next morning men discovered that the Orcs were gone and that a new hill had been raised, piled with stones. It was believed that the slain Orcs were interred there, but no man ever set foot upon the hill and no grass would ever grow there.[1]